welcome to healthcare magic
the reason for your symptom could be you have developed problem of hyperacidity
due to taking many medication at the same time and some of these medication cause hyperacidity.
its not a worm that is moving around in the stomach.
you should also check out h -pylori infection because it can also cause hyperacidity problems.
you should be reviewed by a gastroenterologist for further investigation and appropriate treatment.
hope to have answered your query