If the blood of Christ only pays for Adam's sin then we are all in trouble.
For all have sinned and fallen short of the glory of God and the wages of sin is (the second) death.
So by what means are we saved (according to the WTS) if not by the blood of Christ?
Romans 8 teaches that nothing can separate us from the love of God...
In fact it give a long list of things and powers that cannot separate us from God.
I have come to the conclusion that if none of those things or powers listed in Romans 8 can separate me from God, then I can't either.
So I have no fear of being "responsible for my own". I don't have the power to be responsible for myself.
Peace