My guess is that your relationship is doomed.

1) Nobody should have to "give up" their family because a boyfriend can not adjust to them. And eventually that is what he would want.

2) You probably have traits similar to your parents (in SOME areas of your personality). So, if he hates them - at some point he will be more than annoyed by some of your traits. And you should NEVER change "who" you are for a guy.

3) At 15 - if he is that bull headed to not be more accepting - then he sounds kinda like a jerk (sorry).

Just my opinion. Do whatever you wish. And I truly wish you the best.