Gas pains and uti? PLEASE HELP?

I had a very high fever and chills I had a pain in my lower abdominal and went to the hospital just in case they found out I had a slight urinary tract infection and put me on antibiotics they also told me the fever/chills was because I was dehydrated and gave me iv I felt completely fine and left the hospital only to not be able to keep any food or beverages down when I got home I was throwing up all night 2 nights in a row and had 101.6 fevers I finally got rid of the fever and stoped throwing up but I got really bad gas pains and couldn't poop I finally did but my gas pains are still terrible I tried to eat a sandwhich but I couldn't hold it down also I had some chocolate pudding after and held it down so far.. Can somone please help me get rid of these terrible pains or tell me what's wrong with me I can't take it anymore !!