Wife and husband relation?

I accepted my gf as she is and I married her against my parents will. My wife's parents are very poor. So my marriage happened in one small temple and in a simple way. I am not telling this is the great thing. But I cared for her parents. I am loving her more than anyone in this world. She was also telling in front of everyone that she has all the happiness. Even her parents were jealous of our relationship. I liked to do bit romance with her so much and at the same time I had one weakness, sleeping and she was also the same. We had great ual life in first year. Second year, her ual drive came down and was getting irritated for everything I do. Even if I do some jokes also, she used to get angry saying I am teasing her. I never teased my wife. But she was feeling like I am teasing her, irritating her. In third year, she started scolding for my high ual drive. So I stopped asking for . I heard so many hurting words from my wife for my high ual drive. Even I tried to communicate with her, but she was thinking that I am asking only from her and she didn't express her feelings. In third year only, she told I am not responsible in her expected way and stopped doing sex with me. I tried to come up to her expectations. One of her friend came in to our life and started to show love towards my wife. She told he is like her brother, but I didn't like outsider entering into our personal life. I objected that. Then she started to blame for failing to express my love in the way how her friend is showing. She compared me to him. and later she left me saying I don't know to express my love, I am not responsible, I didn't care her. I cared and expressed my love in all the possible way how much I know, but she was not satisfied with that and didn't want to try to save our marriage. I was ready to mend my ways to express my love. I know we cannot coerce other person to love us. But one question I have, when wife is expecting to care her, love her, same thing if husband is also expecting is that wrong. Before thinking that he didn't care me, it is also good question ourselves how much I cared for him. Did I give what he likes. When I was coming from office during late night, sometimes I was hunger, but she didn't cook anything for me. She used to tell I am getting sleep. Whenever I was asking her for sex, she was telling she is not getting mood. I asked her to dress in a sexy way at my home, she refused for that. When I also didn't get any care I also could have gone to someother girl. But I wanted to be with my wife till my death and never wanted to cheat her. I am not telling I am not telling I am perfect man, but I want to tell is both of us should work on that. Now she is living separately and if I speak about working on our marriage, she will try to escape. She doesn't want to discuss on that. If I force, she will behave very rudely. So I have stopped asking her to work on our marriage. where she want happiness she can get from there. I have no issue for that. Tell me why someone (not everyone) are like this?