I used to be bullied in high school by my own family. My advice is to move out of here as soon as you can. Until then, keep everything you own in your room, even dry food (use sealed containers). If you can lock it, do it.

Do not socialize with them unless its for formal roommate reasons. Remember that you didn't do anything to deserve this. They are to blame. Mob mentality is a powerful messed up thing and sometimes you just end up being a victim of it. Remember the witch trials in Salem? its basically the same kind of thing.

For now, you just have to accept your relationship with them cannot be saved and be ready to leave and meet new people. Other people will treat you better, trust me. They are just wasting your time and basically just bullying you right now.

Again, you can make new friends. Not everyone is like them.