My advice is this:
~If you believe that you have issues that are preventing you from having a healthy relationship, then you need to resolve and deal with those issues first and foremost. I would consider seeing a therapist, and if your ex has similar issues, talk to him about the possibility of him seeking a counselor as well. If you really love each other, and the issues are what is getting in the way, then resolve the issues.
~First love is hard to let go of. Period. He may be the one, or may not be...but for those of us who didn't stay with/marry our first love, those special people often still have a place in our hearts 10, 20, or 30 years later.
~If you are absolutely sure that this relationship isn't going to work out...and that you need to break up, then you need to cut the ties so that you can both move on. I am not saying to never speak to them again, though. I have remained friends with some exes, but the key is, you have to have a period of time to move on without the interference-2 months, 3 months, 6 months, etc. with no going to each other's houses, no phone calls, kissing, etc. You need a separation period for a while, to move away from the boyfriend-girfriend relationship, if you would like to eventually have a friendship. There needs to be boundaries for a while.
My mother was very unhappy in a relationship that she was involved in for about 10 years, and they weren't happy, but couldn't separate, either. She tried dating as well, without cutting off the first relationship completely, and it always failed. I finally told her that she wasn't going to find anyone else, or anyone better-until she stopped being with the current person. Her big thing, as it turned out, was that she was afraid of being ALONE and not having that crutch/support system/comfort of that familiar person being around-long enough to enjoy and learn about herself for long enough to be "whole" for when the RIGHT person came along.
I don't know if that helps...but I tried.
P.S-Once my mother finally did cut the ties of that old relationship and really got out there on her own, unexpectedly she met her future husband a few months later-and she wasn't even looking for him.