your husband is joint owner of flat . he has 50%share in said flat . if you are not in good terms with your husband opt for divorce by mutual consent . in consent terms your husband can bequeath his 50%share in flat to you . gift deed can be executed for husband 50%share of flat in your name .
even if you dont want divorce husband can execute gift deed/ relinquishment deed in your favour .
if husband is acting violently and threatens you then you can obtain protection order from court . file Dv case against your husband