In Ecclesiates, the bible talks about there being a season and purpose under heaven. Perhaps your season is over with that woman. Love and friendship are supposed to lift you up, not emotionally drag you down and cause you to avoid. When you married your husband, it was between you and him, not you and him and them, so perhaps it is time to cut the ties and cleave only unto your husband and find new friends. Give yourself some credit, you complied and tried to be friends....but your Spirit is telling you that something is wrong with the friendship. Better to listen than to suffer emotionally and mentally!