I'm overwhelmed by the depth of his feelings. He's said outright he wants it to last forever as it is now. My feelings are not so clear. I enjoy every minute with him. I don't want my time with him to be over at the end of the evening. But he's married. I refuse to let myself fall in love with him.
From this it seems like you're not sure what you want from him beyond the present. It's okay not to know that yet, as long as you let him know that's how you're feeling. Maybe you don't need to make any decisions about this. As long as he's not moving away tomorrow, you can perhaps keep things as they are, since you are both enjoying it? If he does move, then you should discuss whether you're going to end the relationship or perhaps do an LDR? Not sure how feasible that would be.
I'm not sure what you mean about the last part about him being married and your refusing to let yourself fall in love with him. Is this because you're not comfortable with his situation? Would you prefer a monogamous relationship with someone you're in love with?
Sorry I perhaps projected too much about the relationship with his wife. Since you didn't specify, I wasn't sure what the barrier might be to your having a longer-term relationship with him. Seems like your lifestyle differences are the barrier, so there's not much to be done about that, except enjoy the relationship as it is for now, and keep looking for someone better suited to you in the long term if that's what you want. Your boyfriend will need to understand that he can't be that for you because of these differences.