What happened with my apartment neighbor and is there any hope?

In the last couple weeks I found out my apartment neighbor, and I mean our doors face each other and are three steps apart, is a guy I used to work with several years ago! (of ALL of the buildings this was just a weird coincidence) So he immediately asked for my number just in case one of us was being too loud or something, but then he began texting me quite a bit. He's also a regular at the coffee shop I at & has work meetings there occasionally. Anyway, he's always been a really decent guy but when I finally hung out with him we talked at my apartment and then he began cuddling me. He tried to kiss me later and I was caught off guard and backed away. He told me he respected my boundaries and that it's okay. But when I walked him to the door I gave in and we kissed which led into intense making out. I didn't hook up with him and he went to his apartment and went to bed because he worked the next day. Well, later that night the next day I had never received any text from him so I sent him one asking how work was because of course I noticed his car wasn't outside and he hadn't been home all day/night. He doesn't have a girlfriend either. He ended up responding and telling me that he had a job interview out of town that day, even though the night before he was agreeing with me when I made my intentions clear.. I told him I didn't want to be the girl next door that he casually hooks up with and he said he didn't want to be the guy who's just the casual hook up either. He wanted to see where it went. So I'm confused and I was super upset, I definitely overreacted but I mean, he's looking for jobs in other places? I was trying to text him about it and I'll admit, I made the mistake of probably coming off clingy after he broke the news to me. I was hurt, I still am. So I've been trying to play it cool and act like I don't care, I even thanked him for respecting my boundaries, told him I'm talking to someone else (just so he doesn't think I'm still crushing on him like crazy), and told him I want to be civil. He was perfectly fine with all of that.. but now I can't even have a casual friendly conversation with him. He just doesn't want to talk to me I guess. GUYS, I'm a mess over this guy and I can't stand it. It doesn't help that he lives right next door. Literally I can hear him and it makes it harder for me to get over whatever that was. I just want to know what the hell is going on in his head... I have my **** together, I live next door, I'm not conceited but I know I'm attractive and have a lot to offer, so what the hell?