Is it ok to hate my mum?

No you are not a bad person you just have anger built up inside you that you don't know how to handle. Now please don't take this the wrong way but please seek help in a professional. they are trained to help you put those emotions in prospective and help you deal with them and find out why you are dealing with them. If you are ever to find a guy that you are in love with you may never be able to feel the full love for him because you have so much rage built up inside it may hurt your relationship very badly.