I am having some issues that I was hoping you could provide some advice with.

Thursday morning around 4-5am I had unprotected oral sex with a CSW who I'm pretty sure is an IV drug user. She wouldn't take off her shirt because of a "bug bite". I don't believe that it lasted very long. Maybe a few minutes, and I masterbaited myself to completion. I was drunk and completely regret my desicion, but I can't take it back and have to live with it. Friday afternoon I started to notice a red spot on my foreskin (36 hours after). It's smaller than a pencil eraser. I didn't think much of it, Saturday it was still there so I went to urgent care where they said they didn't think it was herpes, and he pretreated me with a shot and zpack. When I asked what I thought it could be, he said he wasn't sure, pimple maybe. My questions are as follows 

1. Is 36 hours too soon for a spot to show up? I keep finding conflicting information.

2. Will the treatment clear any infection I could have gotten from the exposure (ghonnoreah, ngu)

3. The spot looks like it's around a bunch of blood vessels. Like they kinda feed into them, but it also looks like there is a white dot in it when I stretch the skin. the redness kind of disappears when I stretch the skin. What could this be?

4. Am I at any higher risk since she was an Iv drug user? (HIV)

I apologize, but I just am having a hard time finding clear information online 

Welcome to the Forum.  I'll be glad to provide some information.  Your partner was a commercial sex worker.  While at higher risk for STIs, most CSWs do not have STIs and oral sex only relatively rarely leads to infection.  When it does, the most common problems are either gonorrhea of non-gonococcal urethritis NGU) caused by mouth organisms introduced in to the urethra during sex.  The shot (most likely a rug called ceftriaxone) and the azithromycin you received would prevent/cure any typical bacterial STIs you might have gotten, i.e. gonorrhea, chlamydia, NGU and syphilis.  That leaves viral STIs- your risk of genital herpes from this exposure is very, very low and 36 hours is too early for HSV to appear.  The "official" risk for HIV, IF your partner had HIV (you do not know she did) is less than 1 infection per 20, 000 episodes of receipt of oral sex (i.e. like having sex with an HIV infected person once a day for over 50 years) and thus is not something to worry about.  Further answers to your specific questions:

Would it also be evidence against the spot since it showed up Friday and hasn't changed much? I could rule it out?

 Also, just to make sure I'm clear. Even though she was a higher risk csw, it doesn't mean I was at higher risk due to the nature of exposure? 

Nothing you describe suggests that  the lesion you have described is herpes.  And yes, if it were herpes, it would have changed since Friday. 

You need to relax.  Really.  EWh

I did have one last question.  I did see that there is a risk for HBV (hep b) from oral sex especially with IV drug users. But other where I've read that there is no risk. Is there a risk?

Glad to hear that your spot has faded. 

Receipt of oral sex is not considered a risk factor for acquisition of hepatitis B.  I would not be concerned at all about it.

I encourage you to move forward without concern.  As you know, now with this being my 3rd response to your questions, this thread will be closed later today.  Take care.  Please don't worry.  EWH