If HKBH takes such a view that he’ll allow a husband to overrule a wife’s neder (which is otherwise an issur d’oreisah) with regard to such matters, surely He’ll overlook it if the OP doesn’t want to shave her head because it will cause shalom bayis problems in her home.
Another proof is from Sotah.
If it will make your husband upset, don’t do it.