Deedeee,

Cleveland Clinic give a good overview: https://my.clevelandclinic.org/health/diseases/10352-diverticulitis

Mayo Clinic has instructions on how to recover from a diverticulitis flare-up and what to eat afterwards:
https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/diverticulitis-diet/art-20048499
It is important to have confidence in your MD...or even to get a second opinion IF you think doing makes sense. If so, find the right kind of MD on the Castle and Connolly website. They list the best MDs based on research. The Healthgrades websiite reports what conditions an MD treats most often.

I know that kind of gut pain is difficult. I was told I had diverticuli in my 30s. While my current MD said I no longer have them, to this day I cannot eat fruit skin, strawberry seeds, etc. If I so, it feels like something sharp is moving through my gut.