How long do you think a man can go without sex

Genuine question.. I have zero sex drive as is- maybe once/twice a month I’d help my husband out but since having a baby it’s really plummeted. We had many infertility battles, as I deal with endometriosis. I don’t really wanna be touched, rarely even kissed. Definitely don’t feel ready for sex. Baby is 2 months old. She’s always with me and I nurse. Our marriage has been rocky the last two years I’d say. My grandma said if I’m not doing * wifely duties* he will seek it elsewhere. Do you think this is true? Generally speaking