What Causes Fever Along With Headache And Abdominal Pain?

Im not feeling well, i have been sick for about a week. First it started off with a headache, then migrated to a fever and sore throat, then a fever of 101-102ºF. I need a new eye prescription for my contacts and glasses as well. I don t know if this has anything to do with it, but i ve also had hair loose. I consulted some friends and a doctor and they thought it was seasonal but its been going on for 2-3 months. And i m a little weak, i can t do much. I get a little confused in a way that i didn t used to. And some abdominal pain and more gas than usual.