Your concerns are entirely justified and I feel you handled the situation correctly.
I also think you'd be wasting your time and money trying to make this work out with this particular therapist any further. Unless you can be given a legitimate reason why she's dragging feet about it, it's time to kick the dust off your feet and go elsewhere if you can. I really hate to say this also, but if she really did word it exactly as "people who start TESTOSTERONE via informed consent do not fare well"... my objective impression is that she has a personal issue with FTM's and it is clouding her judgment of your care. That should never happen under any circumstance. That is dangerous and highly unprofessional and I completely agree with Beth, you should definitely report her conduct to the licensing board. Don't allow this abuse to occur to anyone else if you can help that. And you surely can just by creating record of the misconduct.
And incidentally, her claim is without merit. I'm 99% informed consent and doing great (maybe that just chaps their butts that they're just unnecessary for some of us, I don't know). The only thing I had to do with a therapist (actually, the presiding head M.D. Psychiatrist overseeing the entire mental health department of Kaiser. Before which a year previous I'd been basically lost in the shuffle of a LCSW at the same place who clearly wasn't going to help me. Didn't even remember me from two weeks previous, or else pretended not too... trying to peddle me off into other things I just really didn't need and was not there for) was because of Kaiser's policy to cover their butts. It was simply an assessment to gauge whether or not this was a sudden decision possibly brought on by mental instability (and that is a more than reasonable and fair precaution IMO. It is as much to protect us as it is to protect them). It wasn't and so the same evening I received a call with the decision, stating she didn't believe I needed therapy for this as I'd clearly had it all figured out on my own (and I also was perfectly honest about my preference against therapy during our meeting. Honesty is always better than trying to reinvent the facts, until or unless you have good and justifiable reason otherwise. But I will warn you that they are trained to pick up on dishonesty or hesitation and THAT is a sure-fire way to guarantee a slew of therapy, not to mention outright "gate-keeping") and she had even already set up my second appointment with the Endo for me. That was that; quick and painless. I only wish it were the same experience for everyone. That's how it should be. Patient's will should always come first until or unless there is a LEGITIMATE reason not to handle it that way. And if there is, you have every right to be told that reason or reasons without any beating around the bush about it/them. You are paying this person for a service, don't forget that. For your time with that professional, you are their boss. You have the power. Use it. And if you're unable too because of unprofessional conduct or otherwise, that's a problem you do not have to and should not have to put up with.
Furthermore, I would be very cautious about signing anything. The only reason I can think of for why she'd need you to sign releases to obtain your medical information and only now would in fact be to contact your doctor(s) for nefarious purposes. By law they're not even allowed to discuss you with ANYONE else including your doctors until or unless you sign those release forms (this DOES NOT include letters for T, however. Those are to be written and to be given to YOU, so that YOU can then present it to your medical professional and for it THEN to become part of your medical records. NOT any other way). I really wouldn't do it. She clearly has no interest in following-through. And two years? Woe.
I truly am sorry you've had a negative experience but don't let this snowball any further. Get away from this woman. Her conduct is extremely unprofessional. And I'm simply shocked moreover because she's one of us herself. Talk about gunning for your own. I bet she'd not have appreciated someone just like herself in the reverse hanging it above her head and having to act the trained monkey to get it either. That's wicked. Or maybe that's the problem, maybe that did happen and now she's exacting revenge. I don't know. I'm not keen on trying to figure people out like that. In any case, it's wrong and you don't have to put up with it.
Since you are already on T and with a record of informed consent (hopefully you do have a copy), you don't have to continue therapy at all unless of course you wish too. A letter from your present informed consent physician stating you are already on it and the reason why is enough should you ever have to find another provider for this care, for whatever reason. It's likely better to be from an Endocrinologist however, as they're more capable of providing specifications about the target range of total testosterone as well as other particulars.
As for already having told your prescriber to expect the letter, I'm not so sure what you should do. Perhaps you don't have to do anything. If you're already informed consent and you've signed for that, and its part of your record, that should definitively be the end of it and no further explanation should be necessary for the lack of the therapist's letter. I also don't have one from a therapist but my Endo's letter has proved more than satisfactory (although in hindsight, I do really wish I'd have requested the inclusion of the other reasons I need it just in case. Without it my insulin and cortisol just go nuts and sickeningly so. I'm not just saying that. But alas so far that has proven unnecessary. Hopefully I won't regret that oversight).