Sorry you are going through this with your husband....the others have given some solid guidance.
I would suggest that you get some help regarding codependency/enabling in a counseling setting; alanon; narcanon; etc.
Educate yourself on addiction (read some of the stickies above) and perhaps pick up a book. Codependent No More by Melody Beattie is a classic.
You husband is in there alright but you never know if/when he will appear-you need to learn to protect yourself/son emotionally, financially, etc.