My bf says he wants to be an actor ?

Has he ever showed any interest in acting before? Did he have an interest in theater and films in high school? Does he actually show an interest in the craft of acting? Or is he just another unrealistic wannabe who wants the fame and fortune without doing the hard work? If he truly has an interest in acting, and has previously taken acting classes and participated in theater productions, then he should pursue his dreams. Just make sure he knows he has to keep his day job. Make it clear that you have no intention of supporting him financially. If he’s never showed any interest before, and isn’t interested in actually being an actor, then he’s just a childish little boy with a childish dream. Lots of people decide they wanna be actors because they think it’s glamorous and they wanna be rich and famous. In reality, most actors wait tables to actually pay the bills. Lots of people move to LA to be actors. Only the ones with real talent and determination have a chance to make it in that business. And even most of the talented, determined actors don’t ever get a paid acting job. I think your bf needs a reality check. Maybe he should spend some time with some actual actors so he can get an idea of what being an actor is REALLY like. It’s definitely not all red carpets and paparazzi. It’s mostly a lot of hard work for no reward, and working for minimum wage to pay the bills. 

If you feel this strongly about it, find another boyfriend.

You told him how you feel. It's his choice now. You or the career.

I think it is better for both you and him to break up. You'll accuse him of wasting your money.   He'll accuse you of holding him back or of not believing in him. Neither of you will be happy.

Do him a huge favour and break up with him now.

You evidently don't care about him or love him.

Break up.  You don't love him, nor want to support him.  Support does not necessarily mean financial - it can just mean emotional.