How do i know if my love is helping or making matters worst?

I am a lesbian and me and my girlfriend have been together for almost 2yrs...she use to be a dog and never really had a faithful relationship, she was with people but they all cheated on each other so now she has grown away from that and decided we were going to go from friends to life partners...she cheated because they cheated first and hurt her and instead of her leaving she decided to stay but It just made things worst, so they played the part but were with others until the couldnt stand each other anymore...now i feel like im being pentalized for their screw ups because if somethings looks suspious like what they did, im sneaky or trying to play her...but im not...i have cut and cropped my life to make her comfortable and secure but it seems to make things worst..we fight and argue, when all i want is assurance and romance but of course your not use to that because your use to creeping..so im trying to give her what she has never had but in return i want her to learn me, trust me and romance me.