Congrats, that's amazing! And for you to get a refferel so quick, you're lucky! I didn't have to wait long, but when I called around for therapists, they all told me they didnt take insurance, charged about 200 USD a session, and that it would be about 6 sessions or so before getting a letter (plus paying for the session for the letter). I was lucky enough that one therapist I called was trans herself, and pointed me to a clinic specializing in LGBT (mainly the T part) and took insurance and have letters the first session. But this is a great step on your wonderful journey of becoming YOU. The doctor wil tell you the pros and cons of HRT (not every trans person does it) and make sure youre ready health wise, but it'll be great! I remember starting testosterone weekly shots and getting all excited when a new little spike appeared on my chin 😀 heck, I still get happy when I see darker/more facial hair and its been 5 years! (Granted, I stil have barely a beard but meh) I'd recommend staying in therapy if you can afford it or if you need to find another that takes insurance, is cheaper, etc, do it. I know hormones are different but having different ones than what your body produces will be a dramatic mood change i was encouraged to stay in therapy for 6 months because of my history of depression and anxiety. Depending on how often you take the hormones and how you react, at least at first, it'll be an emotional rollercoaster, so make sure you stay around supportive people and have support systems in place. Besides for that, good for you, and you will be happy once it all starts kicking in. Its a wonderful feeling to know you're even an itty bit closer to becoming the person you feel you really are.
All the best,
Adam