Colonoscopy with APC. Why so much pain?

I have attached 2 pics. The first pic is a month old when I was admitted in hospital for abdominal pain. Actually I have had UC for last 3 yrs and now I was told that it is SRUS. I have a lot of pain and I bleed lot. I was suggested APC. Second pic is the colonoscopy with APC done 2 days back. Doctor was shocked to see the change in a month. Ulcers increased alot in sizes and intestines were all red with blood. All these in a month. I was told that it would lead to cancer for almost 10-15 times yesterday. I'm afraid of this now. Coz ulcers grew alot in size. And theres just mucosa and blood everywhere in intestine, that's wt doctor said. Also apc was very painful, it is still paining a bit to sit even after 2 days. Also I bled immediately the following day I got apc done. Wasn't it supposed to stop bleeding? Why so much pain? Doctor said I take alot of stress which I do, and asked me to enjoy the life a bit and also see psychiatrist , I'm already seeing psychiatrist for last 2 yrs.