My sons father angry with me after a secret I kept for 15 years?

15 years ago when I was 15 years old I gave birth to a little boy and when my parents found out about it they moved me to Florida with my Grandparents because they were ashamed. So I gave birth in Florida and I told my boyfriend at the time I was their helping my grandparents out. That was a lie obviously. A miracle happened last week and my son found me on Facebook. Anyway I told my sons father today and he lashed out on me saying if he knew he had a son he wouldn't have allowed my parents to make me give our kids up for adoption. I have lived with regret for 15 years. How can I get my ex to understand the situation? Also my current husband has asked me for a divorced b/c he felt that he should have known. Should I have told him?