After coming out to yourself?

Depends on what you define coming out to yourself. This time is the time, though, that I feel I need to tell my parents. t least my sister first.
After having first knowledge? That was 9-10 years ago
After knowing what transgender was and believing myself to be? Nearly 4 years ago.
After gaining the confidence and the don't give a s*** what others think attitude? It's been about 3 months.
It all feels too late for some reason.

I determined I could be TS around 20 years old, my first disclosure was to my primary doctor at 33, first to family at 34, last to family(as in everyone had been notified) during thirty five.
So, around fifteen years. If I had a "better" situation the timeline could have been greatly compacted, specifically therapy. I would have discovered sooner, that I wasn't possibly-TS, I was.

edit added: I had gender unusual behavior as early as six. Nevertheless it took some time to learn about myself, again, in a tough family situation.

Let's see if I can recall the timeline somewhat correctly. I've included some general history, since I just couldn't stop writing

I came out to myself sometime in the winter 2007/2008. A few months later I came out to a few friends at a party, even though I still hadn't figured out where I belonged on the TG scale.
In late 2008 or early 2009 I joined a local TG group, and soon after my first meeting there I came out to my sister. Throughout the following year I slowly came out to more and more friends.
I think that in the summer of 2010 I told a friend that I now knew I was TS and that I would seek treatment.
Late 2010 or early 2011 I went to the company doctor (combined GP and psychiatrist) and asked for a referral to the local gender identity team. He told me that it was a bad idea, and that it would only lead to a suicide. So I spent the rest of the year in deep depression.
Late 2011 my office needed to downsize, and I could choose between staying there or getting one year off with pay if I chose to study instead. I chose college, so I could start my life over completely.
I worked my last day in january 2012, and a month later I saw a psychiatrist to get a referral to the gender identity team, and two months later I had my first meeting with the team's psychiatrist.
Around january or february 2013 I came out to a friend at school while talking on facebook. She's my best friend, so I wanted her to know before everyone else did. And when she mentioned something about changing her last name I told her about my future name change.
Up until the first few months of 2013 I kept telling myself I would come out to my dad "next time". And when my psychologist wanted to have a family meeting in may with any family members I wanted to bring, I decided to tell my dad and ask him to come to the meeting. As it turned out, my sister had already told him.
In june my psychiatrist called to tell me that I now had an official diagnosis and that he'd sent out referrals for HRT, voice therapy and electrolysis. The first thing I did was to go online to submit my name change application. After that I sat down and wrote a facebook post about how I'd been feeling the last 20 years, and that I was now finally getting TS treatment. The post went out to my extended family, my classmates and a few old friends who felt important to me.
And finally in august the school changed my name in their computer systems, which was the final step of the coming out process.

from what former classmates told me they kinda knew already and the few that didnt i guess i told them like it was no big deal in 5th grade

2006 I came out to my close friends like, right away. Then other friends soon after, and really almost everyone including old childhood friends I hadn't talked to in forever lol. Then 2008 or so, both my sisters and their husbands. Didn't tell my parents until 2012. At thanksgiving I might tell my nephew, we'll see how it goes.