Gastric attack

Yesterday night, i felt uncomfortable after dinner. Guess i ate too much or ate something i should not eat. I suspect is the Oyster i ate. I felt like vomit when i think of the Cheese baked Oyster now..... yuksss.....
At night, i ate a gastric pil. But still not feeling well and it get worse late at night. I cant sleep because of the gastric. I keep feeling the pinch of pain. I wake up and wanted to take a pain killer. I felt like suffocated and breath faster. Then i throw out. Feel better after i vomit, but my stomach still pain.
Take a pain killer and try to sleep. Still.... cant sleep the whole night. Then i decided to take on day of.