What is your mum like? You should try sitting down with just her, or her and a non-involved person if you prefer, and telling her how you feel. Perhaps you could work things out, because you cant go on feeling like you dont belong in your own home. That is one of the worst feelings you can get, and maybe your thoughts are justified, or maybe you just need to all sit down and get to know each other. You wont know until you try talking to your family, the ones you care about, about how you feel.

Hope this helps, and all works out well for you
~Fennikusu