Why can't I get on with my life?

Why can't I get on with my life? My father has schizophrenia and I just turned 18 a few months ago. Ever since then I started googling the symptoms of the illness and now I have convinced myself that I am going crazy regardless of what my doctor and psychiatrists tell me. I have had an MRI done, the doctor tells me that my ventricles are normal and I will not develop schizophrenia. I go to see a psychiatrist, he tells me that I display no signs of schizophrenia, and that it will most likely not develop, but that I show extreme signs of "anxiety". I have a negative cycle of thoughts that I can't seem to shake, and it has distracted me from living my life. Everyday has been a constant struggle of sadness and anxiety bringing myself down every time I try to be happy. All of this has been going on for the past 2 months, ever since I researched the symptoms of schizophrenia and that it is a genetic illness. I keep comparing the way I think and feel to schizophrenia and questioning my sanity every second of the day. Help me, I can't get on with my life.