OK so I feel like what I'm saying makes no sense even just writing it down but I can't find anything on Google or anywhere.

I'm getting a job soon which will have drug tests. I DON'T DO DRUGS. Yet I have this horrible feeling I'm going to fail it and I can't convince myself I have nothing to worry about. Only thing I can compare the feeling to is walking through airport security and feeling like you have carried something you shouldn't have, like you know you haven't but you're so uncertain about yourself.

Has anyone been through this sort of thing, why am I feeling like I'm guilty when I know I'm not and what's a good way to overcome this. Curious why I get like this at all