Edge, your doctor owes it to you to give you the best care, regardless of whether you are trans or not. It is up to them to treat you no matter how you tell them. Your own words, "I'm trans* and want to start hormone replacement therapy" says it as well as any.
Are you ready for hormones? I don't know of course, and I don't know you except through a few hundred Susan's posts. But based on what I've read from you, I will say this:
You are probably one of the most contemplative, introspective, careful people here. You know yourself well, your battles with BPD, your bad and good choices involving your ex, your reactions to trauma suffered in your past. You're a reader and a thinker and you know the pros and cons of T - It's a one way journey but it has the power to transform.
If ANYONE is capable of deciding whether hormones are right for them, it would be you.
Good luck, Edge. My thoughts are with you.