What Could Be The Reason For Soreness And Tiny Red Spots Around Penis Head?

I've been going to the gym for 3-4 weeks now and I've been doing a lot of cardio to try and lose weight. The past week I've been experiencing soreness and tiny red spots on and around the head of my penis. My family doctor believed it just to be rawness from exercising but he didn't feel it to be necessary to look at. I've only had one sexual partner fir the past ten years so I figured it wouldn't be a std and I have no reason to believe that I would have something but I just found out that my best friend of 15 years was diagnosed with hiv and now I'm having every bad thought in the world. I would appreciate any advice on this matter. I don't know if I should get tested for anything or if I'm just overreacting due to the news about my friend. Thanks for any help.