Last week I got really bad back pains it has since stopped that could be because I lift heavy things at work, but it also have really bad cramps and its not my period it hurt so bad I couldn't walk and I wanted to vomit, I am not eating much at the moment because I am not hungry, I sometimes feel like vomiting randomly, I am very tired, I have had unprotected sex recently, and I saw a doctor a few weeks ago and the did tests so its not a urine infection its not an STD or anything like that as I have been checked at the start of this year and I have been with the same since then, I have booked to see a doctor but can any one help me while I wait? What's wrong with me?

Possible flu, sounds like some of the bad ones. But that is just a guess. Since it could be so many things