Welcome to the forum. I'll try to help.
The main STD that can cause genital area lesions similar to this is herpes. However, herpes rarely starts in the pubic area or other hair-bearing areas; the initial lesions almost always involve the areas that receive the most friction during sex, i.e. the penis itself (and the vaginal opening or labia minor in women).
You give an excellent description of typical symptoms and signs of pubic area folliculitis, i.e. inflammation/infection of the hair follicles. This fits best with the location and the association of some lesions with hairs, and indeed your pubic area shaving might be part of the problem. Shaving can cause minor scratches that give staph, strep, or other bacteria a foothold to grow. And folliculitis and other superficial skin infections also are more a problem when the involved area is moist and warm, as you describe.
I suggest you avoid shaving for a few weeks. If the problem recurs, wash frequently with soap and water and keep the area dry, e.g. with talc or cornstarch in your underwear. If that doesn't clear it up, see a doctor or clinic to confirm the diagnosis; some cases require a few days of an oral antibiotic prescription. But based on your description, I really don't think you have any serious worries about herpes or any other STD.
Best regards-- HHH, MD
Thank you very much for your prompt and detailed response!