We're all a work in progress and we strive to do better, once we know better. The only ones who should be wracked by guilt are those who continue in the same course once they are aware they've gone wrong and those who refuse to acknowledge the effect they've had on others.
People throughout the world raise their children with their family or cultural ways and in the religion that they believe in and you were no different. It's what parents are supposed to do. I'm not saying that he doesn't have a legitimate complaint but you may have raised your son as a Lutheran or Presbyterian and he'd have had a whole different set of things to attribute his troubles to and it would be no less or no more, your fault. Imagine what complaints a kid who was raised as a Christian Scientist may have when he or she leaves, especially if he was denied medical treatment and ended up with long term consequences.
It seems (as it is with many) dependance on a religion may have left him with a case of arrested development. When he left the religion in his 40's, he may have only had the emotional maturity of a much younger person. Being a JW who believed they would never grow old, made it easy for most all of us to plateau emotionally and not face up to lifes realities little by little as we grew up. Instead, we had to face these realities all at once. Many are never able to face this and stick with the religion long after they no longer believe. Both those who leave and those who choose to stay, sometimes turn alcohol to ease the utter pain this causes. The thing is, this could have happened with just about any religion depending on how deeply involved one became with it.
I'm guessing you didn't hold your parents responsible for the outcome of your life once you were an adult and didn't expect them to solve your problems and wouldn't even have wanted them to. It seems to me that all you can do is acknowledge your son's pain and let him know you are on his side.
Get some counseling yourself and see what a professional has to say about this situation. Maybe do a little research on "arrested development" and see what the treatment for it is. Typically it has to do with drug/alcohol addiction but it can be attributed to just about any activity that short circuits or hinders a persons emotional development. It may be helpful to become informed on Cults and the residual effects left on a person once they leave one and what it takes to deprogram them and free them of the guilt/fear they may still be carrying.
Growing up a JW definitely has an effect on a person but there are millions who've come through much worse and gone on to have happy lives. If you continue bearing the guilt, it may give him the idea that you are responsible for the outcome rather than him.
