Surprise Sigmoid Colon Abscess: Questions before my resection

Hello.... my story has a few spin offs, kinda related, so I'll try hard and make it concise. It started with a right hip replacement surgery September 27, a successful, uneventful 3-day stay. At home, 24 hours later, I had severe urine retention, and what I thought at the time excruciating bladder pain due to UTI, which I get five times a year. My PCP sent me to emergency, where they removed 550 cc's of urine, but no infection??? A CT Scan uncovered a perforated sigmoid colon with abscess, caused by Diverticulitis. The surgeon would not operate because my total hip replacement was so new that the fear of an infection in the new artificial joint took precedent over the colon resection surgery. Hip revisions are a terrible, bed ridden, months long process, so it was determined that the first action would be to pound me with IV antibiotics and a clear liquid diet. I was also diagnosed with Sepsis. My resection surgery was put on a back burner until the hip had time to heal. Five days later I was released with a regimen of 875 mg of Augmentin 2x day for the next 30 days. Infectious Disease doctors indicated antibiotic regimen "until resolved." My follow up three week CT Scan showed the abscess had increased in size. The perforation had healed, but the antibiotics were not affecting the abscess. I then had an emergency X-ray guided probe to drain the abscess. It was aborted because the doctor placed the probe in the wrong spot! My abscess is still there.
It's now three weeks later and with a Diverticulitis flare, the pain is back, not sleeping, back on high dose antibiotics waiting for resection surgery date December 14. I went all liquid diet yesterday to see if pain would subside. It did. I ate a half bagel with cream cheese this morning.
Now for questions for you....
1. Can anyone share their "safe" diet pre-op with me. I am afraid of another perforation, but I must say I miss eating!!
2. Has anyone been on high doses of Augmentin for several months??? Any bad side affects? C-Diff? I am eating Activa most days and taking a probiotic.

Thank you all. I'm glad I found this site. Like all of you, I have a lot of healing to accept. I must be patient.