Why am I still confused about my ex?

I broke up with my ex (first real love) two years ago, but we have been seeing each other now and then since then. Whenever he contacts me I start to get more obsessed and worried about him again. I think about him all the time, wondering what he's doing and what he's up to, and I miss his company. The problem is that he puts me on edge and makes me nervous, and we didn't treat each other very well in the past, we were still young and immature. We were very close and even now we still have some sort of chemistry, even if I don't see him for months. We have similar minds, both idealists and I love all these aspects about him, his personality and mannerisms. I used to hate him after we broke up but was always deeply attracted to him and I haven't met anyone else like him. I try to avoid him to have peace of mind and to get back to normal and not go through these crazy emotions again, but I love his company. The problem is that I can't fully be myself around him because I feel I need to impress him and it's annoying. I also can't think clearly or well around him sometimes so can't function as well I would want to with him. He has such a strong affect on me, but I don't think it is love. I don't really know HOW I feel about him. We are both quite intellectually intelligent, and I have trouble mixing the intellect with emotions, so I end up getting very confused. Sometimes he's too cerebral or rational and I feel I can't keep up with him because I feel too stressed and insecure and fragmented, with all these emotions flying about. He's an ENTP and I am an INFP, so he's the thinking type and I'm the feeling type and I'm sometimes scared that we're not on the same level or wave-length. People tell me I'm very bright but I am still scared that he's more intelligent than me, in fact the thought of that drives me crazy, because it means that he has more power over me or something. He can also be quite intimidating when he wants to be. I just am not sure how he works. I want us to be equal. I also wish we could just be mature together and understand and respect each other etc. This is making me very confused and insecure and I don't know what to do. Should I see him again and try to solve things, or stay away and move on? Should I have him in my life? I'm worried I won't find someone like him again. I get very passionate and attached to people I care about. Am I just blind and putting him on a pedestal? Is this just obsession and lust? And why can't I think clearly at all concerning him?