There is nothing in your description of your husband's rash etc to make me think he has an STD. It's probably more likely that his fungal infection itched and he scratched it himself, perhaps unconsciously or during sleep. You know your husband and I don't. If you have other reasons to suspect he is having sex with someone else, you'll need to decide whether and how to deal with it. But I wouldn't base that decision on his skin condition(s).
As to his ringworm, has he seen a health care provider? If not, or if it was a long time ago and he hasn't been rechecked lately, he should see family doctor or a dermatologist. Almost all rashes like you describe can be easily treated and controlled; the ointments and sprays he is trying on his own might be doing as much harm as good.
Good luck-- HHH, MD