For goodness sake, Francis---please talk to someone about all this already!
You say you know it wasn't your parents who abused you---so why haven't you talked to them about all of this? Is it the fact that you've been smoking weed that makes you fearful of approaching them? Re: the weed---I'm not going to lecture you about it but instead strongly suggest that you google the side effects from smoking so much of it. I'll leave it at that.
If you don't want to talk to your parents about all this---how about going to your guidance counselor at school? If you don't want to do that, how about calling the hotline number? You would be anonymous and the person on the other end of the line can give you some good, solid advice.
It's very obvious that whatever happened to you was traumatic and has had a profound effect on you.
Please get going --- talk to your parents --- or your guidance counselor --- or the hotline --- or another adult you trust --- just do something! You need to get to the bottom of this!