Wife leave me alone what should i do?

I married past four year.after some month my mother in law died. after some time i have problem with wife. she insisted to doing study .but i dont want to let her. because i need her company.but she choose to complete her study and gave time to her family. we have also sex problem. my wife didnot like sex. i sacrifice for her . but after many months she didnot want to do sex.i have a daughter. before two year she eloped to foreign country with out intimating any one of us.no one know where she was.she left alone me and my daughter .after one month she come to india to her father 's house. she wanted divorce. but i denied. after one year she ready to live with me. she came with me . but after two month she once again left me alone. this time she take my daughter with her. we try alot to search her. but we couldnot find her. it is 8month since she went. i dont know where she goes. she also didn't contact us. i love her n daughter very much. i cant forget her.what should i do. please suggest me