Is there any way to fix a dysfunctional relationship?

over the years of this on and off again 6 year relationship i have began to recognize a very dysfunctional pattern. we fight(usually over my jealousy), our relationship seems to be based on Fear, jealousy, obsession, non-involvement, manipulation, distrust, suspicion, disrespect and an uncaring attitudes. i have tried explaining to my partner that our relationship is terrible and that it probably will not last or it will end just like the last time since we have alot of the same issues present. alot has hapened between us through the years and alot of times i ask myself why we are dating. i can feel changes in my behavior and my self esteem and noticed that i tend to not care about myself as much in general when i am with this person because i have alot of resentment over the past that i feel like i may never get over. i am not a jealous person when i have dated other people between our break ups. in fact, the last time him and i broke up for about a year, once i got over his betrayal and started seeing somebody new and besides that i was just doing better for myself all around. its like when him and i get too involved with achother it just drains me of energy and ambition. his initial presence makes me feel insecure and unsure about myself. I have talked to him about all this and he says its just because i dont want it to work. Is this true? Is there something wrong with me? or is he just bad for me? normally i think im very pretty and smart and all of the above but when i get with him i lose my will to live pretty much and dont care what happens. i know its unhealthy but how do i stop it!