AZmom, my father (who is 62) had diverticulitis a few years ago. He does fit the stereotype (no exercise, overweight, eats very little fiber) though, but when he was in the hospital for it his roommate who also had diverticulitis was about as far from the stereotype as you can imagine.
When my dad had it, he didn't know it at first and thought he just had a stomach flu or something, for like two weeks. He finally went to the doctor and they decided to give him antibiotics while waiting for his test results. My dad then passed out/collapsed while waiting in line at the pharmacy for the antibiotics! Luckily the pharmacy is in the hospital and they took him straight to the ER and put him on IV antibiotics.
Anyway he had a recurrence after his first episode with it and ended up needing surgery to remove the infected area, which was pretty unpleasant, but
AFAIK he hasn't had a problem with it since then, and no longer has to eat the seedless diet. I don't know if your doc has you doing it, but after his first episode my dad was told not to eat anything with seeds as they can get caught in the diverticula. Nowadays he takes fiber supplements but I think that is the only change in his diet since then.
Hopefully yours will get cleared up soon and you won't need surgery!