STD or yeast infection

[heyyyy619]

So, my symptoms started about 2 or 3 weeks ago. I noticed my scrotum and the bottom half of my penis were very dry and started to flake off. Two days passed, and this opaque thick white stuff appeared on my testicles and had a not so pleasant fishy smell (something I have never smelled before). I took a shower, and all the dryness I experienced was gone (I though maybe the skin peeled itself off). However, this happened again a few days ago. I took a shower again and it was gone.

I though it was something like a yeast infection, so I bought an antifungal. The day I bought it, a red painless bump appeared. I have been using the antifungal for about 5 days, and I have seen massive improvement there is still some stuff that is down there when that area becomes moist. But The antifungal cream says to use it for a total of two weeks. The only thing is the red bump is getting less red and drying out, but is not totally gone. So I am getting worried that it could be more than just yeast.

I started to look up different STD's and I am scared it could be more than just a yeast infection. I should say I did have oral sex with a few guys about 3 or 4 weeks ago . However, I did not swallow any of their fluids. Also, I gave the oral sex, and I do not have any sores in my mouth that I can see or feel. So, I am confused, if I do have an STI, how it would have gotten down there. I am mostly scared of syphilis because it matches my symptoms minus the whole white opaque stuff.

My symptoms : dry scrotal skin, thick white opaque "stuff" on scrotum, and red bump that appeared after the first two symptoms(nothing is itchy, I don't have pain urinating, no discharge from penis)

[heyyyy619]

Does a syphilis bump usually start to go away within a week of using an antifungal cream?

Stuff usually says it the bump takes 3 weeks to heal. So if it heals in about 1, is that a good indication it is not syphilis?