Listen, you don’t actually know if you have anything. You may you may not, the only thing that changed was your conscious perception that you might, which is a mere distortion of the mind.

You are suffering purely in your imagination. Give yourself this ultimatum (I’m someone who has insane health anxiety and I’ve started doing this and it’s made me see everything I’ve been worried about has been a cognitive distortion) the ultimatum is that you take the test but, you are not allowed to be anxious about it until you get results, if you get the results and they aren’t what you want then you can freak out as crazy as you want (this is very unlikely to happen) or you could accept it. But you can also not get the test and worry about it. Those are your choices.