So first, if you only received oral sex, your symptoms of an STD would only be genital. Anything you are experiencing on your mouth, face, underarm, etc., are not related.
Some of what you are experiencing could be from covid, and you should follow up with your doctor.
The symptoms you had the following day are not from an STD - no STD appears that quickly. It takes at least 2 days for symptoms to appear. You probably had some irritation from the toilet paper. Toilet paper in public restrooms is notoriously cheap and irritating.
Oral sex is considered a low risk event. Most experts don't think a single act of it warrants testing. The only things you'd be at risk for are gonorrhea, chlamydia, NGU, syphilis and genital herpes type 1, if you don't already have oral herpes type 1.
None of the symptoms you have sound like any of those things, but if you are so concerned, see your doctor and get tested. That's the only way you'll know for sure.
Update : i saw small like whiteheaded pimples on my foreskin