Help me please

I’ve been tested for stds twice and both came back as negative. I wanted to get tested again but my doctor told me that I am clean and to not think about it so much. To come back in 3 months, but I can’t seem to get over it. I am still scared and have anxiety over it. Do you know how to help what I am feeling. I get headaches a lot and my tonsils feel so tight like I am being choked how do I get over this. Please help I want to be back to the way I was.