Will we last? should I trust him?

You don't have to do either necessarily, but you do need to take a step back and not rush into anything. DO NOT MOVE IN WITH HIM! This relationship has all of the warning signs of failure, and you really do need to seriously consider where it's going. Write down everything you want in a spouse, and don't settle for anything less. I'm willing to bet that he lacks almost all of the things that you want in a husband! Between the flirting, the emotional immaturity (having mental breakdowns when you want to break up), the religious differences and the family thing, it sounds like the only reason you're together is because you're too scared to break up with him! Staying together because you don't want to see him have a mental breakdown isn't a good reason because you're sacrificing your happiness and your future for someone you don't truly love. Try telling him you need some space and gradually pull away from him, then a breakup won't seem so out of the blue for either of you.