My UC started with just the sigmoid colon and rectum being involved before spreading to the entire colon. I tried the biologics, but to no avail (it was determined my colitis was refractive). The thing with biologics is that they are purpose-grown antibodies and, as any other foreign protein, your body will eventually reject them. I had started to produce anti-Remacaid antibodies by the time I elected to have the surgery.
Sometimes I wonder if I could have tried something else, but then I go and look at the success rates for some of the more interesting treatments and they just aren't very encouraging. It sounds like you're in the same place I was in about a year ago: The treatments aren't working and you're fed up with feeling awful. If you decide to have the surgery, I wish you all the best.