//Heavily inspired by "lullaby for a princess" and "Sight for sore eyes", and some of my own mental issues of self-doubt that I think the princesses would have experienced, and writing about how they would overcome these feelings has helped my look at my own mental health from a better perspective.
//This story is dedicated to all my friends on the /mlp/ TF2 thread, I wont namedrop specific people here, yall know who you are, but my experience with them also helped to inspire this, and it wouldn't exist without them, so thank you! - LD

--Uplifting The Moon--
Canterlot, by any metric, was an extremely busy place, with the seat of Equestria's goverment located in the mountainside city, the ponies that both lived and were visiting there spent every hour of the day doing something, or going somewhere. They rarely slowed down to relax until the setting of the sun, after which the whole capital city finally goes to rest. On any other day, this was the time that, while the busy city finally rested, it's even more busy ruler finally got a well deserved reprieve. Raising the moon into the sky was something Celestia always did alone, as it marked the beginning of the night, and was the last official act she took as Princess of Equestria each day. But, with the amber sunset's rays casted through her castle windows, today was different. Today, the sunset was her last duty, because after one thousand years of raising and lowering both the sun and moon every day, Celestia was finally reunited with her sister. As the sun descended into the horizon, Celestia turned to face her other half, the long shadows cast by the setting sun darkening her normally majesting, white face like the guilt that has haunted her for all this time, and which haunts her even more when she has to face what she did, looking Luna in the eyes. It's almost too much for her to bear, but you don't hold something against yourself for a thousand years without being able to hide it, and she works through her own troubling thoughts to offer her sister a warm facade, smiling as she says:
"You know, you don't have to raise the moon tonight if you're not ready, Luna, I have been doing it for a thousand years now..."
Where Celestia was in complete control of her emotions, having quite enough time to prepare herself for moments like this, Luna was almost the complete opposite. She's been very recently thrown back into everything after spending such a long time alone, her sister's forgiveness has helped her immensely, but she's been through so much up to this point, and deep down, she can only blame herself for everything that's happened. While Celestia's guilt came from hurting someone she cared deeply for, Luna's was so much worse. In her head, she was the problem, her own hatred and jelously made her take the form of Nightmare Moon. Even now, she stood in her older sister's shadow, a never ending reminder to her that she was inferior, she was the younger sister, she was the one that fucked everything up. Standing in Celestia's shadow only reminded her of these horrible thoughts, bringing them back to her, making her doubt herself. Celestia, while she couldn't read minds, could easily read Luna's face, and changed her tone slightly, taking things a little more seriously, hopefully in an effort to ease her sister's mind.
"I know you can do it, Luna, come out on the balcony, I will help you."
In Celestia's eyes, she hoped that offering to help her sister and raising the moon together would make it easier on her, but in Luna's perspective, it was as if she was talking down to her. Luna's guilty thoughts focused in on the negative, she didn't even do it intentionally, but finally being alone with Celestia now pushed out all her deeply rooted self doubts, putting a kind of wall inside her mind that prevented her from moving forward and moving on from her traumatic past. Breaking down this wall is what Celestia knew would be the most challenging task, and for her, one of the hardest things she had ever done. The princess of the sun stepped out onto the castle balcony, the fading orange glow of the now almost set sun surrounding her. Luna walked out after her, following her elder sister as she had done for most of her life, and hesitated a moment in the doorway. Celestia looked on at the horizon, not wanting to directly face her sister, feeling her own darkness creeping in. She revealed a single, exhausted sigh to her sister, unable to hold her stoic composure forever.
"Luna, you know I've forgiven you."
"B-But sist-"
Celestia cut off her sister's protest, with a barely noticable tremble in her normally very calm voice, she still didn't look back to face her
"You don't have to be so hard on yourself... I understand how you felt, all those years ago, and I understand how you feel now, after so much time alone."
Celestia then turned around, looking back at her sister's face, illuminated by the final fading rays of the sunset, with tears in her eyes
"I should have never done that to you, Luna. Every night I've had to look at the moon and think about what I did to you, every night was a reminder of how stupid I was."
At this point, the tears had already began to race down Celestia's face. Luna rarely saw her sister get emotional enough to start crying, and most ponies never saw this side of her in their entire lifetime. Luna felt terrible for this, knowing how much it took to make her sister emotional, the pressure that it took to break her was incomparable to what she felt, but seeing this side of her sister is what finally calmed Luna's thoughts, knwoing that she wasn't alone, she wasn't the sole cause of everything that happened. The last rays of light from the sun slowly faded as Celestia took a short breath, in an effort to compose herself, and continued on,
"But now we can... m-move on, Luna. We're together again, and I promise you that I'll never do anything like that again, I don't want to lose you again."
With her sister exposing how she truly felt, Luna had calmed down, walking out onto the balcony, feeling the cool mountain air. Luna's self doubt still clung to her, as if it actually made her legs heavier, her steps more cautious.
"Are thou truly not mad at us, for what we've done, dear sister?"
Celestia let another low sigh escape from between her lips, taking a seat down on the stone balcony, facing the outside world once again. By now, the sun had completely set, now finished fading below the line of the horizon, with the last of the light along the edge of the sky finally starting to fade away. Now, the night was beginning.
"I could never blame you, Luna, you were neglected and I put the needs of Equestria before my own sister. I always felt as though it was my duty to protect everyone, but in doing so, I hurt the pony I cared about the most."
Luna stepped out next to her older sister, with Celestia sitting down, they were both at the same height now, all along Luna had seen herself as smaller, like she could never compare. While she wouldn't get over a thousand years of self hatred in just one short fanfiction, Celestia's honesty did make her feel much better about herself, and for the first time in a thousand years, she didn't feel alone anymore. 
"Celestia, we do not blame thou either, we acted very foolishly as well..."
"And that's fine, Luna. We can't keep beating ourselves down for our mistakes, we both have to move on from the past, it seems."
Celestia stretched out her wing, gently resting it down around her sister's back, pulling them together in her soft, feathery embrace, with a teardrop falling onto the stones below them, forming a small, heart shaped puddle.
"Luna, I love you, don't ever forget that"
The stars in the night sky sparkled, the constellations coming into view in the darkness, The two sisters stared into the vast, dark expanse in silence for quite a moment, before Luna finally broke the calm quietness
"The night sky is beautiful, is it not?"
"It is. But I think it's missing one thing."
"What is that?"
"The moon!"
And as the busy city of Canterlot finally went to sleep, the only sound heard throughout the city was the laughter of two mares, as the moon finally rose into the sky, a little later than usual.