Suggest Treatment For Severe Diarrhea And Vomiting

After eating a grilled vegetable sub ( ingredients were black olives, lettuce,tomatoes,mayonnaise, mushrooms, green peppers, and provolone cheese...NO hot peppers or onions) on sub roll , I had SEVERE stomach pains, terrible diarrhea and vomiting, heavy sweating, headache, and weakness. This started a few hours after eating, and included no other foods and iced water and about six ounces of light prune juice, ( an every evening before bed and with final meds for the day ritual). This was not a new meal or new medicine. I was sick like this for 2 full days, (and even became more than a little scared) since the severity did not let up until the third morning.Today is day 4 and praise God I have just been very tired and still carrying a headache. I have been very thirsty (which I understand) and now a little hungry, but I am hesitant to eat anything more than toast or crackers. Could this have been food poisoning? ( the sub was from a place we have ordered from other times...but no more.) Any advice? Since it was the weekend my doctor was unavailable...so, any thoughts?