Relationships

I have been on and off with a guy for about two years now. He was my first everything basically. I don’t know that my feelings for him are genuine, because when we are off I’m not sad, but I do crave his attention. One night we had sex and he basically didn’t acknowledge my existence after that and told me he wasn’t looking for anything anymore. I understood that, so I removed him from my life by unfriending him to make it easier to get on with life. Flash forward to now he got into contact with me telling me how much he misses me and still has feelings for me. He doesn’t talk to other girls, and hasn’t since we split. Not that it would really matter if he did because he had the right to. But I honestly don’t know if I should be giving him chance after chance? When we are spending time together I question whether I’m genuinely interested or if I’m just attached because he’s all I know. Is going back to someone time and time again wrong? Has it ever worked out? I had such strong feelings for him, we got on so well and had such a physical attraction and he was so protective. We went through so much together and helped each other out an awful lot, but as of now I think we’re entirely different. I’ve been on other dates, but how to you differentiate genuine feelings and an attachment?