If so, do you find you just can’t bring yourself to go? Even when family and friends offer to accompany you?
Is there guilt because this ritual is one a widowed partner is "supposed to observe"?
Actually, there are no rules about this. Although some faiths mark the end of the first year of mourning by observing a memorial for the deceased, visiting the gravesite is otherwise a very personal choice.
While some people find regular visits comforting, others find it too upsetting and choose not to visit. Some visit only on special occasions or holidays.
As with all other aspects of mourning, you should trust your own sense of what feels right for you.