I Am 61 Years Old. I Fell Into A Serious

I am 61 years old. I fell into a serious drug addiction starting at age 51+- followed by alcoholism for several years. I' drug free for over 5 years and alcohol free for 9 months. I went through several years of erectile disfunction which seems to have fixed itself; however, I find myself not being able to produce any semen. I get almost the same feeling of an orgasm but that is all. I asked my (new) doctor by he had no clue. Help!