I don't think it's ever too late to start living authentically which can of course mean different things to different people; the aim being that you aren't concealing your true self from the world.For some that may be regular cross gender expression while for others nothing short of a full transition will do. In either case, it benefits you to live in the open because hiding does not help the psyche in that you always feel uncomfortable with keeping something so intrinsic to you as a secret.
Today I live with a much healthier mindset because my children and my close friends and family know I am trans. True, I don't make a habit of announcing it when out in public, but that would be akin to pasting a sign on your forehead announcing something to people who don't know you and don't necessarily care.
If you are with a non-accepting or partly accepting spouse, I really feel for you because that can be very difficult and I lived it. However from my vantage point of today I can emphatically state that I would never go back to that way of living.
In the end, I have not lost one single person who matters to me after coming out which, at one time, I would have never believed could ever happen.