need a third party perspective

ok...here it goes.

he is a cancer sun/scorpio moon and i'm a sag sun/aries moon...so already, astrologically, it's a horrible match. fire and water just don't mix. we have these heated arguments, usually me starting it because i'm so open and he's so closed. i do have a hard time expressing my true emotions (that i really want to be with him) through words so i usually express it physically. we've been "together" for about 10 months now. we both have our faults in the relationship and i've tried to end it many times because it just doesn't seem like we're good for each other but i find myself going back to him because i really do care for him. he's recently been trying to end it with me as well since i've been somewhat jealous and possessive and i know it's a problem, but since he disrepected me once before (by sleeping with some girl because he was mad at me...we weren't together and he made it clear what kind of relationship that we were having...but at that time i really fell for him, but of course i didn't tell him), i have a hard time getting over that because i've had a hard time with trusting men anyway. i know i don't have any fault in his actions, he really shouldn't have done that, but i do have some faults in the relationship too because i'm a bit manipulative at times. i'm wondering if something like this could get better or maybe there are some steps i can take for backing off. i feel like it could work out but we just totally misunderstand each other at times. we really don't know what's keeping us together. we've talked about it many times. i don't know if he's scared of completely letting go or i'm scared. i need some insight.

1-i'm a heartless bastard
2-find someone you get along with