Hello,
Ive been in your spot before amd then i met some very interesting people that made me realize i could have been a lot more interesting my whole life. You are actually at a good point in your life. You need a little spicing up, take this time to develope yourself. Being alone can actually be a good thing for that. Find some interests, learn some skills, listen to music. Although right now family may seem like everything its really not. It may be easier to really find yourself away from them. Will you be going away for college? Which adds to my next point the best and easiest way to change is to change your environment, create a mew box for yourself, new people that you meet dont know who you were in the past you’ll have an opportunity to be natural without predisposed judgments.
Dont be afraid or shameless to feel stupid, your just being vulnerable and thats an important thing not to hide.
Right now it also sounds like you may be in the habit of pitying your situation, which really in the context isnt so bad. When you hear yourself telling yourself how terrible things are or when you get that down feeling snap yourself out of it and say you wont pity yourself anymore. Once you gain control of that habit you will feel a little.better. I never thought of it this way but a lot of how we feel is created and can be changed by disciplining the way we think.
Try to meditate, look into self hypnosis, pull yourself out the well no one will do it for you.
Im saying all this because ive recognized it in myself and am still spending time to fix it but above is what ive learned and has helped me, take away what you can from it.

P.s. This is from a phone so please excuse all the typos its a little broke