420- Married with mentally ill wife

Hi sir, I got married in 2011. I am handicapped but i am an educated and working in IT field. At the time of engagement My in- laws told me their daughter has only one problem " she cannot speak clear..and rest is fine." I agreed that time. I was thinking, i am working and i can support a person. But after marriage i came to know she is mentally sick and she cannot hear properly. That time her age was approx 23-24 but she was not mature enough. She was like a 8-10 years kid. She dont know how to handle anything...i still manage that time...and every year condition gets worse for me. She was always fighting with my all family member. When our first daughter born and she rejected to give her milk..and we gave her cow milk and my mother take care of my daughter.. now my mother is also 63 years old and she is taking care of my both the daughters. I am working in gurgaon. And my family living in amritsar. My in- laws cheated me and my life become worse.. I am very disappointment with my life... pls. Suggest what i can do...