Problem with Mother!

Recently i have been not sharing the same kind of relationship i used to with my mother. She was the only person in the world i trusted the most. And i relied on her in difficulties and usually she would give me strength in tough times. She got operated before 5 years and was diagonised with womb cancer. But she recovered quite well after that. However, emotionally her behaviour has changed and she has become less caring and difficult at times. I am not able to relate with her the same way i used to. Also she keeps finding fault with other people. Even though i tried to support her during her difficult times and made her feel better, now she doesn't accept me either for my behaviour as an adult. I am trying to get along with my life in my own way and she doesn't like this. Although i said i am there to support my family and her, she wants me to stay with her or she wants to come with me wherever i go. She is also having a difficult relationship with my father and he makes it worst as he is himself a difficult person. I don't know but somehow my parents are not able to empathize with me or people in general. They find flaws with everyone and every little thing and can't accept other ppl for the way they are. I did my best part to help it or fix it but i am quite young and don't understand several aspects of relationships myself. All i want is my parents to live the same normal life they used to before. But somehow, i am loosing faith in them and am moving away from them. Any advice would be helpful.