PLEASE HELP ME 10POINTS?

OMG i dont even know where to start from...Its been going on for about 2 years it leave and it comes back I have such fear for cancer im only 18 and my life is being ruined with everyday worries do I have cancer why is my head hurting why am I sick everytime something happens I always think its cancer I have uti I went to do the urine test but they found nothing so the doctor told me to do a deeper urine test and right away I start panicking because im thinking isit cancer isit std I get so crazy I bent down yesterday to pick something up and my lower back started hurting I don’t know what it is its maybe a kidney because I had uti for about 2 weeks and I think the infection got into my kidneys and now im being worried if its not ovarian cancer im writing this and im crying nobody is able to help me please any of you help me get my life back to normal I am soo tired of this I mean I get dizzy and right away I go searching the net for what could be wrong and all I see is the word CANCER I want my life to be back to normall