I understand exactly how you feel... I can't sleep at night unless the conditions are absolutely perfect. It's been that way for a very long time for me. Since I started having nightmares every night as a kid. There are still some nights where I can't be around mirrors, water drains, animatronic toys, windows, and especially people. A lot of these behaviours held strong even last year, when I myself was fifteen. Don't ever feel that your age has anything to do with your fears. Even the most mature and grown people are afraid of something. Over the years I've found things that help me cope with my fear. I sleep in a lofted bed, and it keeps me from being on the floor, giving me a sort of "safe perch" from which I can survey my entire room. It also means that there is less space between the surface I sleep on, and the ceiling, which always makes me feel more secure. If you have very supportive parents, you could try to find a means of getting a lofted bed for yourself. That failing, you could try "boxing in" your bed with a canopy or curtains. Remember, less space means less space to worry about. Develop a safe zone, or a "home base" of sorts, and learn to defend it from your fears. These monsters, because they are your monsters, are absolutely under your control. They grow with your fear. Remember who is in charge, own your fear and you will own your monsters. Confront the things that scare you, and they will have no power over you. As for your fear of the dark, I myself am light-sensitive, so I can't be around bright lights or sunlight. As a result, I spend a lot of time in the dark, and I can see just fine in it. I'm terrified of being in brightly lit spaces, however, because in them I'm blind. Is it really the dark that you are afraid of, or is it just the things that are unknown to you because you can not see? I have plenty more strategies I can recommend, but this post is long enough so I'll end it with this:

We all have fears, and if you will allow me, I would like to help you in any way that I can. Even if it means you just need someone who will listen. I know how terrifying it is to live with that kind of extreme, crippling fear. I also understand how difficult it can be to be ashamed of being so afraid when you feel like you should have grown out of it. Sometimes, a friendly stranger can be the best person to talk to... I know I've found help that way before. Whatever you do, never give up fighting. Keep holding on, and remember to be proud of how far you have already come.

~R