Just quit going. Thats what I did. My family eventually got used to the fact I wasn't in their little club anymore. If your friends don't want to associate with you anymore, well, then were they really your friends? Besides, with 7 billion people on this planet, you can easily find new friends, real friends who don't care what church you go to or if you even go or not.
Why be miserable and unhappy? It's your life, you only get one, make it the best you can. Yes there can be some pain in making this adjustment, but better to get it over with than to be miserable the rest of your life trying to do what other people think is best for you.
No Apologies