That's a great point.
I'm assuming you're Christian, and that's supposed to be all about forgiveness.
I'm not religious, but I think lots of people who are true believers get so wrapped up in trying to not sin that they forget the Church is supposed to accept everyone without judgment and that God forgives all as long as you ask for that forgiveness.
I remember that much from Sunday School.
I think it's the people in the church who were judgmental, even though they sinned as much as anyone, and sometimes more, that made me not want to go anymore.
And, if God did truly make children pay for the sins of their parents, not a one of us would be sane, and that would be a God I wouldn't have anything to do with. That would be horrible.
Now, religion aside, let's look at logic for a moment. If your son is ill because of what you did, then what the heck did the rest of us do to deserve this?
You're depressed & with depression comes a feeling of guilt. You need to see someone, whether it's through your local mental health center or a church-based charity. There's plenty of free healthcare out there, but sometimes, you have to really look for it. If nothing else maybe talking to someone in the church would help? Even if you're not active, I've never known a pastor or minister who would turn someone away if they were in need.