I am going to be honest with you that, I had a similar relationship like that, but now we are happy and healthy in term of mentally and physically, I will share a little bit about my story, then I hope you can get something out of it, I had been always mad and angry with my girlfriend about small things because we have different habits, she wants to change me and some of them I don't wanna change, but it turns out what she wanted me to change is a good thing, so I reluctantly change, what do I mean by reluctantly ? because I try to change but I am not happy with the changes, then the cycle keeps coming back again, and furthermore, I was still studying in university, I am an introvert no friends or going out a lot, I did not have a job...etc I do not have anything interactive with human beings much except just only with my girlfriend, she also was in the same situation, we all stay home and be around with each other all the time, then we all realized this is not good honey, this is not good, we love each other but why it turns out so ugly like this, then we decided to go to work, to keep distant to each other and just see each other 2 hours every day maybe or around it, everyones need some private space to think and do whatever for them, and it is normal, nobody can be around with someone 24 hours without feeling pressure in my view. But now we all have things to do and we see each other less but still we do not neglect each other, we know life is a balance between work and relationship. Now when she tries to correct my habits or mistakes, I feel normal, I think she just wants me to be better, and it is good nothing bad at all, why should I be angry though, and what she had done as taking care of me or recall what she helped just make me feel better and willing to change, but of course, we have to be moderate, we can not correct others all the time, nobody wants to be corrected without giving a praise or compliment, so I would recommend 3 to 5 praise = 1 correcting mistake maybe, it is not an exact number but I think you can get what I mean.
About my sex life, I think we are doing good, after a long day of work, I know me and my gf had been exhausted, nobody is interested in sex or anything intimate anymore, I dont either, but when she is wearing something sexy but try to act cute, i could not resist but instead of jumping in right away, i massaged for her i talk with her a bit like an intimate talk, then we can feel more connected, furthermore, of course sex is not always everything, if someone is addicted to sex there must be a problem and we should look deep into it as well, it could be from boredom and have nothing to do. Then we should together help each other to break it, in my opinion, in a relationship, there may be one wanting more sex than the other but not too much, just a little and enough for us to tolerate I suppose.