What's the possibility of my get this irritation from an STD?

[Ronny90]

Hi I'm a 27yo male but on July 17th(monday) I had unprotected oral sex with a woman which we had random sex. She was really rough with my penis and I did ejaculate. I had slight pain at the tip but nothing else bothersome. July 22(Saturday) I ended going to a party and meeting a random chick there. I'm very cautious at this point because the pain was still present. I always use condoms when having vaginal sex but for oral I didn't. I did ended up hooking up with the chick at the party. The pain continued and I noticed on July 28(Friday) I began to experience other symptoms like back pain, slight headache, clear little discharge and slight pain during urination. My urethra was irritated and dark pinkish but no lesions at all. I used tea tree oil from research on the internet which over the weekend(july28-30) actually help ease the pain and my urethra color begin to come back to normal. At this point I had decided to get tested whiched happened on the august 2. My RPR and HIV rapid test showed negative so far but I'm not out of any trouble yet and will definitely follow up in 2 and a half months. My question is if any, what STD could this be? I've read a lot of stuff on the internet and I can't count it as all true of course. If not an STD What other diagnosis could it be? Could it be chlamydia as opposed to herpes?

[Ronny90]

I also seem to have some sharp stabbing pain in my rectum. It might be my prostate but its been very random. Any idea why?