Does your urine look funny? Is it cloudy or look like there's bits of feces in it? Ever feel like you're passing air when you urinate?
Make sure when you wipe after a BM that you wipe from front to back to prevent any feces from causing a UTI. Always urinate after sex, and drink plenty of water. The older we get the bigger the chance of developing diverticulitis, which can be controlled with diet... it just happens. The yeast infection was most likely caused by the antibiotics. Get a second opinion on having a colonoscopy with diverticulitis, as they can perforate the bowel which is already weakend within the pockets. Hope this helps.