Wait until you’re self sufficient, then tell her. It can be dangerous to do something like that while she still has some control over your life. As for “breaking her heart”, I can’t really give much advice. If she’s getting angry at you for not going to church, if she will not accept you as you are, then she’s not a very good Christian anyways🤷♀️ you can’t be something that you’re not, and she should love and accept you as you are