I need advice.

How to start this. I realized to late that I loved someone after we broke up-we were only together for fourdays- and then recsntly he sent me a text saying he was single again. It's been about two weeks scince he's broken up with the woman. Appearantly he loved her a lot. This person has been my friend for a very long time and soon he's going to Iraq.
Last may he told me it I wasn't with Chris(My ex, whom I was with or 3 and a half years) then he would ask me out.(Missed opretunity one), then a week after Valanstine day he asked me out, we were together for 4 days. Then last week, he told me he was single. I mean I really like him, but I don't want to be someone he dates on rebound. I've talked to him once and he seemed willing...I'm not ready for another heart break and when I'm in a relationship I invest everything I can into it.
I talked to my cousin and she sugsted that I just lend him support until he comes back and then try, But I don't want to miss my chance. I mean what if he gets with someone else? Should I take my chances? I don't know what to do. I'm willing to try again, but I'm not ready for another heartbreak and I'm all about seizing the day. I hate feeling so torn...

So would someone give me their advice? I'd be so grateful.

Love always
Larissa