Can STD Be Contracted Through Non-penetrative Sex?

Hi, About 2 weeks ago I had relations with a woman. There was no actual sex, but there was some genital to genital contact and oral both ways. A few hours later I woke up with what looked like a rash, or scraps on my penis head. I think they subsided but I masturbated a couple of days later and noticed them again. I can t be sure the ever went fully away. They are flat and do not hurt or bleed. It s been almost a week since I noticed it the second time and it s still there, although not quite as red. I have sporadically masturbated here and there but have tried not to. Could this be an STD? To go along with that, about a week after the hookup I noticed yellow skin discoloration under my foreskin and it seemed initially hard to pull back. I should note that I was wearing tight underwear for a couple of days prior because of the penis redness, and did not wash during that time. I begun treating it with an antifungal cream but there yellow is still there after almost a week. Is it smegma or yeast? It s not clumpy, or liquid like, just a yellowish discoloration. I haven t had any pain, itching or burning, so I really have no idea what this could be. Is this likely an STD?