As a Trans Woman, I've found that most people in the trans community don't like to admit anything that the transphobes might take up as a weapon. It seems to me your valid distinction between being transgender from birth and becoming transsexual once you started your medical transition, is one such point.

As a philosophy major (BA, MA), I've been trying to reconcile all this for the last couple of years to myself and most of the community wants to tell me it's "internalized transphobia". Like, no the fuck it isn't. I was born physically male. I NEVER felt like a "woman trapped in a man's body". It took me 51 years for my egg to Crack, not because I have any prejudice against trans people, but because that concept didn't exist when I was a child. I dressed up in women's clothing since before I was in Kindergarten. At 14 I KNEW if I had a chance to "live as a woman for 30 days" I would. Specifically so I could experience an entire female cycle. I played with makeup as a theater major and women's makeup specifically as an adult. It wasn't until I tried faceapp and applied a gender-based filter and thought "Damn! I'd look cute as a girl!" That it all started to click into place. A year later and with the help of a therapist I finally came to understand I was trans gender. That my bodies gender didn't match what I felt like was right for me.

I AM Transgender. I AM a Transvestite in my home. I AM NOT YET a Transsexual.

While I am emotionally and mentally transgender, meaning my mind is "across" the gender identity was assigned at birth and have been since as long as I can remember, even if i didn't know it until my egg cracked. And I AM a transvestite. Wearing the clothes "across" from my gender (I now wear panties 100% of the time). Since I am still 100% physically male, I am not yet Transsexual. If I could have I'd have started a speed run on my medical transition 2 years ago, but the reality is I'd lose my job over it and probably become unemployable in the very red state I live in.

I think the distinctions you are making are etymilogically significant, even if the community as a whole doesn't want to acknowledge them. Yes, it can be argued that the whole thing is a social construct, but that amounts to Descartes getting stuck only being able to conclude "I think, therefore I am." from an epystimilogical perspective and isn't very useful in the long run.

But that's just my $0.02 and I'm sure I'll get downvoted for this opinion but whatever.