I can't say that I have personally experienced this. My body became flatter & boobs smaller in my late teens, but that was due to dropping about 20 pounds and beginning weightlifting.
You mentioned you experienced an increase in hair on your neck, throat, and chest; oilier hair and acne; and 'boy' sweat. I'm not sure of what type of anti-depressant you're on (I'm no doc and have no idea what their side effects are) nor when you began having issues with depression, but: have you ever presented a doctor with these problems? As in a medical doctor, who could run some tests, and not a therapist? The changes you describe seem rather dramatic; they actually seem to fit rather well with the symptoms of PCOS (polycystic ovary syndrome, which results in an excess of androgens in female-bodied people, often causing some degree of masculinization--check it out on WebMD).
I can understand if you didn't go to a doc and happily accepted these changes (I know I would've). But for your health, it's something you should have checked out; I'm not saying this is what it is (again, don't know--not a doctor), but in the case of PCOS, it puts you at a higher risk for such nasty things as insulin resistance and diabetes. I know I, too, would worry that the docs would assume I was complaining about the masculinization and therefore prescribe me estrogen or something to combat it, but... even if they write you a prescription for female hormones, they aren't going to force you to take them. That decision is up to you.
Just because your body has started to head in the direction of teenage boyhood on its own, it doesn't mean you are required to complete the transformation. However, you said you'd lose all sanity if you went back to the way you were before (ie, curvy woman). I guess the biggest question is: do you want to be seen as a man, a woman, or somewhere in between (an entirely valid option, btw)? Testosterone therapy, as I'm sure you are aware, will cause your voice to deepen; you'll drop that 'spunky teenage' look and mature into a man. Even if you're not sure about transitioning, talking to a qualified gender therapist about it wouldn't hurt; they can help you sort out your thoughts and feelings and, if you decide that transitioning isn't for you, no harm done. If you decide it is for you, well, they're the people you need to be talking to anyways.
Oh, and I definitely identify with 'feeling like a fraud.' Every time in the past several years someone assumed I was a young boy, I would have that feeling. I would be afraid to speak because I knew that, as soon as I did, they would take their assumption back. And I'd rather just have them think I was a young boy; better than the alternative. I also had the feeling that I would never grow up because I could not accept being thought of as an adult woman. Anyways, best wishes to you as you sort things out.
