Hello noodlesenpai, welcome to Psych Central.

I feel so bad for you. Please can you talk to a teacher, your doctor or another adult that you trust. I suggest a teacher that you trust, you have been through so much and it almost sounds like a prison where you are right now! Yes there could be a physical reason for the incontenence or a psychological reason for it and as someone has already mentioned, you need to see a doctor for that. You need love and support, not yelling at constantly.