Actually, I knew why, the question was more to encourage you to think logically, why it has to be smth serious?
My guess is you Googled symptoms after your treatment and after that you continued to Google to try to reassure yourself it is not stomach cancer. It is path to disaster and it is the reason you are now here, in panic, and the reason why you "always" go there.
Stop seeking reassurance through Google because it is impossible thing to do. It will only raise your anxiety level and stop you from thinking logically.
Logically, you don't have any reason to be afraid, but you can't see that because anxiety is much stronger. So, in order to think more logically, you need to reduce anxiety. Which means, guess what, stop Googling.