Jenny I can relate because I dated an abusive guy for two years. I tended to isolate myself from my family because I didn't want to hurt them or tell them. I also keep thinking "maybe hell change" but i knew he never would. If you are still with him you need to leave him. Tell your family, ive told my family a few times. Your family will always love you. I know how it feels to love him and its hopeless. I still "miss" him but its been about 4 months now and i can see how horrible and lonely i was with him. You must tell someone, tell the police, tell a trusted adult, tell his parents, or hopefully tell your family. You need them to help you through this if your still with him.
Good luck girl