Dear Mark Wannabe
I read SENSIBLE'S remarks and have to say that they are very sensible, and I'm glad that you are getting both sides of the coin.
However, I believe that people will only, can only, advise you based on their own experiences.
If I knew you, I would be very reluctant to encourage you to go for it in case you failed. The truth is you have REALLY got to WANT to be a commercial pilot to make it.
But here is my short story; no advice, just my story.
When I was thirty six, someone gave me his secret to success. He said, "Decide today what is the ONE thing that you most enjoy doing in your life. Once you have decided that, invest every single day of your life in that ONE thing. Only two things can happen: You will either be a huge success, or you will have at least spent your life doing the ONE thing that you most enjoy."
I am now flying for a major UK airline. I finally got my lucky break at the age of thirty nine. Medical willing, I have at least twenty one years of service ahead of me.
Are you too late? NO.
Should you go for it? It's up to you.
Good Luck