Marathon runners talk about hitting 'the wall'. It's that point in the race in which you exhaust the glycogen stored in your body while using it for the quick energy that running calls for and start burning stored fat instead. That's brings on massive fatigue, and at that point in marathon parlance, you've 'hit the wall'.
There's a wall when you transition as well, but it's emotional. You try to live with the incongruent brain gender body mismatch, but feel more and more out of place and as if you're playing for the wrong gender team.
You feel out of sorts, confused, and disconnected. It's as if your sleepwalking through life. You know that something's not quite right, but can't put your finger on it. You continue to try everything to live as a 'man' or 'woman' in body but not in spirit, suppress that inner male or female by becoming more hypermasculine or hyperfeminine but you're still unhappy.
The frustrations mount in terms of life, love and relationships until you finally say, 'enough' and emotionally crash. At that moment that's when you finally realize or accept the fact that you are transgender.
Hitting the gender wall is emotionally painful and never comfortable. It's a emotional and difficult road with a few potholes in it. But in the end, you end up as a far happier person as you make the moves toward becoming the beautiful person you truly are and were born to be.