Is it possible for stomach virus to stay for 7 months?

Possibly: A viral infection is typically an acute illness (weeks) and at this point you are describing a chronic syndrome (months). As far as infections go, CMV and herpes virus (viruses) and h. Pylori (a bacteria) are associated with chronic gastritis, as well as parasites and more rare types of bacteria. However, there are many non-infectious causes and it may be time to revisit your pcp or GI doctor.

Usually not: If this has been going on for that long, you need to go to a physician asap.