A person without GD, is not likely to transition, and they use the facilities they are most comfortable with, the ones specific to their birth sex.
A lot of people in that position find outlets for their feelings, dressing at home or going to specific groups for example. Manchester has one that meets on a Wednesday in the Village.
Trans folk who are transitioning are very conscious of their appearance and don’t generally want to draw attention to themselves, unless they pass very well we’ll avoid certain situations or alternatives. Gender neutral loos are very sparse, so it’s not the easiest way to live.
The issues around suicidal feelings tend to stem from society. Internally you know who you are, but you know society doesn’t accept you. The terrifying prospect of not being able to be you and instead putting up a fake persona each and everyday is tough. I really wasn’t able to live my life until I was able to discard that pretence.
Regarding medical treatments causing dysphoria, I didn’t say they do, they just can mimic some of the symptoms we experience. When I started HRT, it didn’t take long for me to feel much better in myself, around six weeks. My starting point was a normal hormonal level for a male and is now a normal level for a female. Adding more testosterone would not have helped and could actually have induced a testosterone induced rage.