Wow, that sounds awful to deal with! I don't know how old you are, so I don't know how much longer you're looking at living with your parent(s) (I'm assuming that's where you live.)

I'm guessing you've already talked to your parent(s) about this?

All I can think of to do is to get something large that you can lock to keep your things in when you're not there.

Hugs.