Colon cancer?

The gastro specialist thought I had a palpable colon in the left iliac fossa. Also maybe diverticulitis. Hasn't sent me for tests. The strong dull pain, discomfort in my stomach has just gotten worse over this weekend so worried as to what this can be? It seems to be in the middle of my stomach rather than on the left side of it. Quite sore. Is that significant?

Checked online these two conditions which have quite similar symptoms so difficult to know which one, if any, it is likely to be. Right now am feeling quite sick and the pain is tremendous. Also feeling tired and weak, with low energy and wondering which category this would put my symptoms under.

Worried about the possibility of colon cancer. Haven't lost any weight so far, so wondering if it was this whether I should have done by now? What are the actual symptoms for this and how do they progress? If it is that, how advanced is it likely to be if I haven't lost any weight? Really troubled by this and thinking that maybe a trip to A&E could help as also read that diverticulitis can be quite serious too... can anyone advise?