You'll have to ask your counselor to be sure, but I think she can write you a referral to take to a doctor. If not, then you'll need to see a gender therapist for a referral. If the therapist goes by the rules in the APA guidelines you'll be waiting 3 months before she'll write you the letter. It's also sometimes possible to get T by informed consent, but you'd have to find a doctor who was willing.
Shots generally go in the upper thigh or the butt muscle, and are done once a week or once every other week. Patches can be used, but most guys just go with the shots because the patches can irritate your skin, and like gels and creams they must be done every single day, so it can get really annoying.