I have been keeping Shabbat Rabbanu Tam, because that is what my husband wishes for many years. My background is Polish/Litvak and my husband is Iraqi Edot HaMizrach. All our kids are grown and keep Litvak and it has become more and more difficut to keep Rabbanu Tam hours as time goes by and I feel more and more resentful sitting alone with nothing to do for those 45 extra minutes. Is there any way of getting out of this?
If your husband is okay with it, you can do hataras nedarim (see Maaseh Eliyahu 52), after which you can follow the regular custom of the Geonim/Vilna Gaon.
The hatarah is done by standing – yourself or your envoy (your husband can do it for you) before three men, and asking for hatarah.
The Petach for the neder can be the fact that when you began the practice you didn’t realize how resentful/frustrated you would become, or that you didn’t realize that this will become obligatory practice for you.
According to the Chazon Ish (Maaseh Ish Vol. 2 p. 121) there is actually no need for hatarah, but this is not the common ruling of Poskim.