Separated in Husband's Customs

I married a man who strictly observes the end of Shabbat according to the method of R"T, and I have separated from him. I want to stop this practice. Do I need a release from vows?

Even though a divorced woman, if she stopped immediately upon divorce, or continued thinking she was obligated by law and not by stringency, does not need a release from vows, a separated woman still belongs to her husband and needs a release from vows.

One who follows a good custom and wishes to annul it needs a release from vows, as explained in Nedarim 15. "The Rabbis taught: Things that are permitted, and others consider them forbidden, you may not permit them in their presence, because of 'do not profane your word'." This is because they considered it forbidden and knew it was permitted, it is as if they accepted it as a prohibition, and they violate 'do not profane' by rabbinic decree. And in Shulchan Aruch, Yoreh De'ah, siman 214, סעיף 1, two opinions are brought whether release helps, and it is ruled that release helps for a custom that was followed. And a woman who follows her husband's customs is not considered to have accepted the custom upon herself, as written in Tashbetz, part 3, siman 179, that her obligation in her husband's customs is because a wife is like her husband's body, and therefore if upon divorce she immediately stopped the custom, or even if she continued the custom, thinking its prohibition was by law and not by stringency, she never accepted the custom upon herself, and does not need a release from vows. But when they separated, she still needs to follow her husband's customs and therefore is obligated in the custom because of her husband's acceptance, and when she wishes to annul it, she needs a release from vows.