Guys, how long does it take for you to....?

get over an ex girlfriend? i met a guy in a group i belong to and host. and, upon talking to him (believe me, had nothing to do with what was said either)... i felt attraction, chemistry, locked into his eyes, ease talking to him (hope i didn't ramble too much), and i felt this tangible feeling of peace/calm/joy/healing deposit in me for a few moments then leave... that part really felt supernatural. i swear, not making it up. i never felt that with talking to any person before. since then, we email. there has been slight flirting. then, now we're becoming a little deeper about issues and things. i feel mixed like sometimes i think he likes me, other times he's keeping it professional sounding (maybe since i run the group). ever since the first get-together, he's attended every month since for a few months. but, now i find out he said he broke up with his girlfriend (he told me via email). well, my first reaction is YEY! my next is, i feel for him... and hope he is ok. i really care about his feelings. and next, i wonder, uh-oh am i going to be a rebound IF he does like me and it's mutual? How long does it take to get over an ex? he didn't say how long they were together. i didn't ask. i am wary to talk about the ex's unless he brings it up. i don't want to become therapist or in friend zone forever... suggestions? experiences you can share?? thanks for listening. really care about and like this new guy.