| Instant Success Is Not The American Dream|
First off, the "American Dream" as far as I know has never included "instant" success, so your husband has never been interested in the true American Dream.
You Can't Change Your Grown Sons
Second, your sons are men. Though you can offer support and/or advice to them, they are adults and are already products of their upbringing. If they are jaded or pessimistic there is little to nothing you can do to change their outlook. They have to recognize their own shortcomings and evaluate why, for example, your 34 year old has been fired from every job he's ever had.
Let Him Keep His Delusions
As for your husband, if you love him, let him keep his delusion as to how successful he really is.
Sometimes people say things about themselves because they doubt it so much they hope somebody else will confirm the feeling for them. In this case, maybe your husband doubts his success and likeability and just needs you, his "loving wife" to stand by his side.
All you can do is to continue to be a loving mother.