what is your diagnosis? how weird that they have treated you with that diagnosis for 2 years and now suddenly they can't help you.

Please write to them explaining that you have transportation issues and cannot access the doctor to whom they have referred you, and ask them for another referral. It is their duty to terminate you appropriately and find a realistic successor who will work for you. They cannot just drop you. Apparently they did provide a referral but it is not a realistic option. I would go a little formal and write "I have concerns about the termination procedure. I cannot make use of the referral provided and need an alternative prescriber whom I can access. Until one is found, please continue seeing me for medication management".

If that does not work, go with the above advice: telehealth or infrequent visits out of town.

Also, do you have access to mail order pharmacy that can see you a 3 month worth supply of your meds?