Took strong antibiotics for illness, had hair loss. docs keeps saying they dont know why, won't give advice. can i at least try vitamins, foods, etc?

Of course: They won't help either. Don't overdose on biotin; it's the one that can make you sick. I trust you have recovered from your illness and have had your thyroid checked, and that this is not alopecia areata. Chances are you had telogen effluvium and this self-cures, in an unpredictable length of time. I"m glad you're better. Best wishes.