In what way is this affecting you? Is it when you are with someone and are about to have intercourse or is it when alone pleasuring yourself? Just give me a few more details please.
Have you done the postage stamp test for a few nights (to see if it's waking up overnight when you're likely less anxious and far more relaxed)? If it fails that then I urge you to see a doctor to try to dig into the possible cause(s).