Adults please read...looking for advice on a sticky dating situation...thank you!?

I've been seeing a guy for three months. I'm 30 he's 34. We really hit it off on all levels, he's so thoughtful, fixes everything in my house,texts me throughout the day, just very thoughtful.I thought it was nice to have a guy not pressure me into a serious relationship but now after brining up the exclusivity talk he says he is not ready.a)because he got out of a 5 yr relationship 1 yr ago and wants to be sure before getting into another and b)he is going away for military training due to a promotion for 8 months in May and is scared because his last gf freaked out whenever he left. I've never had a guy want to take it slow so it concerns me.I'm trying to be patient but it scares me to emotionally invest and risk getting hurt. He's really good to me, this is really the only issue but to me it's a big one.I feel like we could have a really good thing but fear if he isn't sure now, he will never be. How long should I give him? Suggestions on how to deal with him? I feel sort of lost.