Are those symptoms of stomach infection?

Hi

I recently caught a flu about 3 weeks ago and I took some painkillers for that. After a few days later, I had a really bad stomach pain in the morning, with the feeling of wanting to vomit and the stool turned dark. So, I stopped taking the medicine and I thought the flu has already gone away. After that I didn't really have enough rest properly and have not been eating well. Also, I consistently have the loss of appetite and discomfort in the stomach. And now, 3 weeks later, the discomfort is worse and I think I also have a fever again. It's worse when I go to bed at night, I sweat a lot and feel like I want to vomit. So I went to see a doctor and he suggested it could be some sort of stomach infection and that might also be the reason why I have fever again. I will have to get some tests done, but I need to wait like a week for all those to come back.

In the mean time, I just would like to know if there's anyone else out there with the same experience and how they dealt with the situation.

Thanks