Pain caused gastritis

I have a gastritis. My stomach is very strong before, since I lived alone, I had a illness. This is very interesting illness. I don't feel any problem, suddenly I feel pain. The other side, I feel pain and cry than my body return to good condition.
In the morning, I feel little uncomfortable. I just think that there are some problems at yesterday dinner. Suddenly I feel little faint and throw up. I feel of pang. I can't stand. My body is trembled. I can't do anything I just feel pain and cry. 10-20 minutes ago, I barely stand up and go to schol by cab. After school, I go to a hospital and take some medicines. I arrive at home and fall asleep.