My husband died 16 months ago. I get migraine headaches from wearing head coverings. Am I still required to cover my hair?
In principle, a widowed woman must cover her hair. However, the halachah concerning a divorced or widowed woman is less severe than the halachah of a married woman. You should make every effort to cover your hair in public, but if this causes you severe discomrort, so that you are unable to function, there is room for leniency. Perhaps try different types of hair coverings, until you find one that disturbs you less.
See Even Ha’ezer 21:2, and Beis Shmuel 5 (see also Perishah, Chelkas Mechokek; Be’er Heitev); see Iggros Moshe, Even Ha’ezer I, no. 57, who explains that the status of a divorcee or widow remains less stringent than that of a married woman.