Need advice/perspective/opinion

I'm 26M and my ex 23F. I'll try to explain the situation as much as possible and here I'm seeking outside perspective. So me and my ex dated on and off for 4 years. We had a lot of fights in between, I always felt that our expectations from each other were always more then what the other person did. My ex also is verbally abusive when she gets angry and will say things that are extreme in the sense like wishing the worst on me but I on the other hand is a bit gentler and I would never say anything that harsh to someone cause I'm always cautious of the other person feelings. Her justification of being shitty to me whenever she is like taht is that I'm not taking her seriously and that I should guarantee her that I will marry her. So when I say not serious I mean that I am taking her serious to be in a relationship but something inside me tells me that the marrying her isn't the right choice because she always cross the line in saying things that hurt me. She says that if I marry her she will treat me good , idk but I feel like these things shouldn't be conditional like you should treat someone good because you love them and not because you gain something from them. She has often used words like ' Be a man ' ,' you aren't a man' because I'm not accepting like tge marriage thing. Now I will say there are probably certain things that I did wrong too but some part of me eventually started not liking her as a person .

Now some context is that she never had a trustable male figure in her family whether it be her dad and then later step-dad and her brother. So I get but I feel like she treats me like shit. This isn't all the time like we do have good times and thats why this question . Now I'm not the greatest too in the way that I did made mistakes. Like before i met her I followed some pornstars and all on instagram and I just started using insta a month before we met so I just like followed them ig cause friends kinda were doing that. And we we started dating I forgot to like remove them cause I actually I'm not that active on it. She got hurt because of it because she thought that's the kind of women I want, so trust issues generated. I then unfollowed them and stopped using insta and other social media for her peace of mind, not that I was using any to begin with but to me I thought social media isn't bigger then the relationship. But I believe that left a scar for her and no matter what I do she says things like y9u might be googling bitches and all with big boobs and all. She says she will stop if I guarantee I will marry her. Does giving assuring about commitment fix things ?

Now the opinion I want part is here, like you read we have stopped dating which i broke up because i felt i was putting too much effort and i wasnt getting the respect i should get . She did come back emotinal and says she loves me and i am an emotional person and haven given in but tge fights later happen again.but now a situation has arrived where if I marry her I will like benefit in some way which the reasons will be confidential. Now I do miss her, we have gone through together a lot and I wonder if things would also get better if we do marry. So now my question is do y9u think I'm thinking of marrying just because I'm in a position that it will benefit me or like because I miss her that can't be the only reason. Also this is my first and only relationship so maybe I'm stuck. And also with her behavior do you think the condition she said once married it will change or these things just stay ?

Any opinion/advice/perspective would be appreciated Sorry for it being too long 😅