I'm sorry this is happening.
First, you should get this evaluated. It sounds like it could be PGAD, but you should make sure that it isn't something like an entrapped nerve or a mediation is causing these symptoms.
If it is PGAD, there are some medications that may work. Therapy also seems to help - this is not that it's a psychological disorder, but stress and anxiety play a role in making it worse. (And really - it's a constant irritation in one of the most sensitive areas on your body - who wouldn't be stressed and anxious?)
Here are some things you can read, and show to your doctor, who may or may not have experience treating it, since it's rare -
https://www.medicalnewstoday.com/articles/249594.php
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4980903/
http://www.sandiegosexualmedicine.com/female-issues/persistent-genital-arousal-disorder-in-women-pgad - this one may be the best. It's got very detailed info on possible causes, diagnostic tools, and treatment options.
Good luck, and let us know what happens.