Have a look at this list of doctors:Does anybody have a list of the doctors surgery's that do the medicals please?
I'm supposed to go to St Mary's in Preston but the waiting list is a joke
https://assets.publishing.service.g...roved_Doctors_in_UK_06_October_2020_v0.24.pdf
SOME, not all of them are DVLA approved for your type of medical. Find one near you and ask if they have any appointments available.
Then get in touch with DVLA and tell them what is available to you. If they say no, ask to speak to a supervisor or you will escalate it to a complaint.