What you experienced at the restaurant does sound like food poisoning. A typical case of food poisoning is one in which the symptoms come on pretty quick (definitely within a day, usually less) and the symptoms do tend to be rather severe, with lots of vomiting
or diarrhea. However, after that, symptoms should settle down and you should feel better. It is possible to feel under the weather after an episode of food poisoning for a few days but then you should be improving. I am not sure from your question how long it has been since you had the episode of food poisoning, but definitely if you are still have symptoms after a few days out, you should go to see your doctor
In addition to food poisoning, which occurs when preformed bacterial toxins in the food provoke symptoms, it is also possible to pick up an actual bacterial infection from contaminate food. This tends not to cause symptoms that are so sudden or so severe; rather, the symptoms (such as abdominal pain, nausea, fever) tend to build up over a few days. This might be what is going on, or it could be something else entirely - your primary care doctor
should be able to help you figure it out.