Yaaaaaay! I'm delighted to hear that someone has reached out and is helping you get a helpful T instead of one who's not beneficial to you. Good luck and I hope things work out with the new T!

The differences:
A psychologist is only trained to council people and does stuff like talk therapy

A psychiatrist is a medical doctor (MD) and can write prescriptions for medication

I'm not sure what the qualifications are to be a therapist but they're not as strict as either of the other two if I remember correctly