Home Environment

I can't continue to ignore the mess. I need a feasible (ie. gentle) plan to get things into order. I know it *could* improve my mood. 
My space is very small at the moment, and none of the furniture is mine. Also, basically everything is broken, except the bed I think (though it might be missing a few pieces here and there, but it holds together). 
The bookcase is completely destroyed, the "desk" wobbles, the closet doors are broken, and the bed is what my 10 year old brother outgrew. We don't have money for new furniture and certainly no money for a new home.
I need to save to buy furniture. Forget about little ditzy purchases like home hair removal lasers. I really need, for my mental and emotional health, to have a nicer, safer, cleaner, more welcoming space than what I am faced with now.
The room is a baby blue with these white wood things on half the wall, I don't know what they are called. They need to come off and the room needs to be painted. It's definitely going to be a step by step process, figuring out what to do first etc. 
I'd also like to change the inside of my closet so that it matches me better. Keeping this closet organized takes so much energy and I feel if I were able to organize it in a manner that I could see everything, I would have better luck with organization. 
The idea of saving and "investing" that here is scary because I do not want to stay here. I know it's not good for me to live in this environment. I know I should not be here, but right now I do not have the option of leaving. 
The relationships with my "family" are completely lost. The losses are irreparable. There is nothing that could fix what broke between us; we're not even as good as strangers for each other. If I could have been born in a loving family, I would in a heartbeat. If I had the option of forgoing everything I have experienced so far with this family in exchange for a loving, respectful, peaceful family, I would never hesitate. I truly do not see the lesson to be learned here or the purpose of the way things are/have been.
It just makes everything incredibly hard for me, and now I have to heal from the effects of things I do not understand.