I think you have folliculitis, which amounts to blocked pores. These are common in the groin, from heat, sweating, etc. I agree with your doctor that they are not an STD. I think you should apply bacitracin or neosporin ointment daily, that you leave them alone and stop picking, and that you see a dermatologist so you can get a specific diagnosis and be able to stop worrying about them.
Take care.
Dr. Rockoff
Please get an accurate diagnosis. I don't think there is nothing for you to be confused about.
Dr. Rockoff