I've been full time for about 5-6 weeks now.
How did I do it? It was a gradual progression from knowing I was different, to trying to figure out why I was different, to accepting I am trans, to going on low dose HRT and liking it, to joining online forums and learning and making friends, to trying dressing up and makeup... all leading to a night when I stepped out in 4" heels and met some friends in the San Diego gayborhood for drinks.
Each step reinforced what I was starting to learn about myself - that I am female and that if I went out in the world representing as such the world kept spinning and no one really cared

That realization led to some serious thinking.
Meanwhile my drinking had ramped up and I was on the quick path to an early grave. I finally accepted that I needed professional help and since I had recently moved to L.A. area there was professional help to be found. I located a great therapist and she helped me to get to the conclusion that I already knew.
I am a transsexual.
That was very hard to accept because I knew what was going to happen, which was basically that my wife was going to say "screw that" and walk out - which she eventually did - and that I was headed toward the waterfall of transition.
Talk about a sobering moment.
But here's the thing - I was happy for the first time in my life. That happiness had started snowballing that first night out in San Diego, and it kept right on snowballing up to the present moment.
So I transitioned.
Was it easy? Nope. Was it hard? Definitely. Was it scary? You betcha - that hit
really hard when I was walking to the CEO's office to let her know my plans - no one even had a clue what was about to happen, and most people were shocked. I could theoretically lose my job. But I walked into her office anyway and made my announcement. And I survived.
Was it worth it? Absolutely.
Have I been accepted? For the most part - yes.
Did it fix all of the problems in my life? Not remotely. But it did get rid of the dysphoria I had been living with for most of my life which has allowed me to move forward with my life.
Has living as a female been challenging? Yes and no. i've found it somewhat challenging to undo 50 years of male socialization and switch into fill time female mode - you find that you are always "on" and your appearance and voice and mannerisms are constantly being judged, whereas before you could dress out of the dirty clothes pile and walk out the door unshaven and slovenly and no one cared. It is a completely different experience, and frankly it takes constant lot of work with your appearance, voice, and mannerisms. But the female world (at least to my experience) is compassionate and I have made some very close and tight/emotional connections with other women. It's way more intense (and complex!) than hanging out with the guys, but I like it.
I've heard it said that life is what happens to you while you are making other plans. I never planned on this and some days it's very surreal. But it beats my old life hands down.