In need of some serious help here?

I am looking for some opinions here, I mistakenly broke up with my fiance a few months ago, I realized my mistake and called him almost a month ago. He was really happy to hear from me and we talked a lot for almost a week and he told me he loves me with all his heart and we even made love. He did tell me that he was casually dating someone, but she wasn't his girlfriend and it was not serious. After we had our emotional conversation about getting back together the next day he did a 180 and has backed way off, but if I ask him if he loves me he says he does, and doesn't want to rule out us getting back together. I think he may be using this other girl to make me jealous too, b/c I have caught him lying about her, for example he said they go out and do fun stuff all the time, but he wouldn't tell me what, his friends told me all he does is go the bar she works at and gets free drinks off her, he also said she met his family and they didn't. I know that when I broke it off with him that I hurt him really bad, and he is bad with expressing his emotions, but I feel certain that he does love me. Is the best thing I can do give him space, or what can I do to convince him to give us a second shot and to help heal his wounded ego?