Thanks for posting! Yes, the eternal struggle of past paint jobs! It can be hard to grow in a space (even as an adult!) and not feel the urge to repaint every few years.
I would say that if you can, cover up the lime green wall as much as possible. A fabric tapestry is a good, expansive option that isn’t too pricey. If you have three lilac walls and one tapestry wall, that neutralizes the room a lot more. From there, I would focus on maturing the pieces that you can in your room. Think not just about what you like now, but what you will be able to continue to take with you and like in a few years! Even if this means you end up getting only a few, nicer pieces, use those pieces to set the tone for the rest of the room.
I also think that you’ll find that if you remove some of the smaller accessories or wall art from your childhood, and have a more minimalist/ bare set up, it will go a long way to reducing the youth of the space. This can also create space for you to bring in more current pieces or see opportunities for them!