When I initially read your story it seemed really familiar. but I feel that we are only getting one sided version. Someone I know seemed to be like your partner. The reason why she was acting like her was one yes she also came from a very unstable household. The guy she was engaged to seemed okay but a bit of a mumma’s boy. He also wanted to sort out issues that the couple had. The girl was really unhappy with the way that the her inlaws were treating her before marriage and felt the only reason that the guy was being decent to her (90%) of the time was for visa issues.
He like yourself was a mosque goer etc…but it was later revealed that the reason why the guy had not resided with his parents since he was 18 was that his parents had kicked him out after he had unknowingly raped 
a girl.
He felt bad for his actions and then decided to be all allah allah.
I am not saying that this is you. But I just view all people that preach to girls who are not hijaabi just because of that a bit KUKU. she may have a better heart and soul than all those other Hijaabis out there.
Sorry but just from my point of view and just needed to vent,…