I hate it!

So, be me, 31, half closeted half not, kinda like a walk in closet thing depending on company.Been like this from my ‘realisation’ as a teen. Been through military service, places I never want to go to again, things I never want to re-live. Trust these people day in, day out. My life in their hands, but feel so much shame to say the words... “I’m gay”. Even writing it here, I look around to make sure no one can see.I now work for a national insurance company (I know... leave the military, join insurance co.... natural step to take). We’re recognised nationally for our lgbt policies and practices (lol).Can’t tell colleagues. The shame wins again.Realise I’m ashamed of who I am for no reason, but can’t shake it. Considered some very dark things and don’t wanna go down that route again.What do I do?