Anxiety colon cancer (or IBS?)

Goodmorning everyone,

I am a healthy man (I hope) , 38 years old. I have a big health anxiety problem in general. I self-diagnose many horrible diseases, especially cancer. Needless to show you all the diseases that I thought I had this year, I assure you they were many.
Now my problem is the fear of having colon cancer. My main symptom is having loose stools especially in the morning, everything I eat different from my usual diet causes me to have softer stools than normal. It's not exactly diarrhea, it's creamy stools. I have trouble having formed feces. I had no changes in the bowel movement, in the sense that I always go twice a day without difficulty and regularly. Never seen traces of blood in the stool, for now. I had problems with meteorism which I practically solved by eliminating above all pasta and bread, but I know that my intestinal sensitivity has increased a lot.
I paid a visit to the gastroenterologist, who carried out an ultrasound of the colon, telling me that the colon does not seem to be suffering and that the walls are perfect, he felt my abdomen without finding masses or pain. He also performed an abdominal ultrasound, where the liver, spleen, pancreas, gall bladder, bladder and prostate were normal. He left me with an examination for celiac disease and gave me probiotics, but they are not improving the consistency of my feces.
Unfortunately, my anxiety is still there after the visit, even though the visit was negative. I read a lot of people who suffer from unformed stools, without having serious health problems, but I know it's not a good thing.
I remember having unformed feces at other times in my life, but now I look at it every day and it's becoming impossible. I know that the only test to be sure is colonoscopy, but the doctor didn't consider it necessary to do it.
Can I trust your visit? I have read conflicting rumors on the net, apparently the ultrasound of the bowel is however an undervalued test that can see tumors and serious problems, to then do more detailed examinations.
I'm confused.
I add that in December I made a proctological examination due to a small thrombosed hemorrhoid, the doctor gave me an anoscopy and told me that there was nothing abnormal and the hemorrhoids were only slightly inflamed.

Any advice or word of comfort would help me, thanks.