All of my care is through the VA. Since they revoked Gender Affirming Care and banned all flags, pins, posters, and other signs saying they will support us, our true allies have had to work within the system.
So, even though your therapist may not be able to put it in your records and bill it with that diagnosis code, they can write a letter and give it to you without putting it in your records. That gives you a written diagnosis that can be used to start HRT with a medical provider, even if they are out of state, and to use a mail-order pharmacy.
Just an idea to keep in your back pocket in case you need it.