Rash on breats/nipples

So my boyfriend sucks and plays with my breasts a lot. In July 2021, I noticed I got a small rash that I suspected to be a ring worm on my breast. I tried over the counter cream which didn’t work. Soon I was noticing more of these little rashes and went to a clinic. I was prescribed some other cream which didn’t work. This the rashes started to get worse & was covered a small portion of one of my breasts. I went back to the clinic & got another cream that seemed to make the rashes go away. But now it’s slowly coming back. Could this be something caused by my boyfriends saliva? He also sweats a lot (not his fault he’s just an easy sweater) and after sex he lays on my chest. Could this be caused by his sweat maybe?