Un-endable Relationship Issues?

Well my best friend (of three years) and I decided to date about two months ago. He has had a huge crush on me for the entire three years that we've talked but I didn't develop feelings until about three months ago. We had a lot of arguments while we were dating but they weren't irrational, we always argued for good reasons, like stuff to make the relationship work better. But one day the argument escalated too highly and I decided to break up with him, even though that's not I wanted to do. I really cared about him, it was just out of anger and because it seemed like it was appropriate for the moment. Our first relationship together only lasted two weeks. And honestly that still was the best relationship of my life. We clicked and connected in ways I've never felt with anyone before. I cried everyday that we weren't together because I feel like I won't ever experience a relationship like that again. I have dated someone for over a year and never felt as strongly for someone the way I do for this guy. The relationship was flawless until the moment we argued. Our arguments became uncontrollable and that was always when chaos broke loose. But after a while, we ended up talking things out and we gave the relationship another chance. But this time, he was an entirely different person during this relationship. He was so much more insecure and less caring then before. I was the only person making an effort in the relationship. We argued daily and our relationship was extremely tense until we decided to break up again. For the remaining month until now, we tried to be friends, friends with benefits, acquaintances, and even nothing at all. But either way, we are unhappy together, and we are unhappy without each other. We can't solve our arguments and our arguments are what screw us over. What do I do?