Hi...when I was a teenager, I would get boils and even a carbuncle on my elbow where there is still a huge scar, every single summer until I turned about twenty. I got them on my buttocks and arms mainly and more than one at a time. I was told they were a staph infection. Never got them during the rest of the year...only summer. Maybe you should ask your doc if an anti biotic will help.
I am newbie and haven't had a chance to introduce myself yet but wanted to reply to your post. Ouch! Ouch! Ouch! Your symptoms sound very much like mine!! I also started getting boils when I was about 20 years old in the very same places you mentioned. I have gotten them under my arms, in my groin, under my breasts, on my bum and around my stomach. 15+ years later and I have finally been diagnosed with Hidradenitis Suppurativa. Not sure if this is what you are experiencing or not but wanted to pass along the info in case it could help.
Take care and hope to see you around the boards!