He can be saved, that agreement can be rescinded, difficult path.
The anxiety is the drain he feels on his soul energy, he's now in a cage.
He will suffer constantly, no matter how much fortune and fame he has. His energy is now being used for evil and he feels it.

Had he sacrificed another it would be a done deal, he wouldn't even be in there anymore. His heart would go black and he would enjoy the suffering of others, it would become his new drug.

The fact that he can make this statement says they haven't took it yet, They only made a deal for his energy, lifeforce. So now, they will be looking for an opportunity to get him to interfere with the will of another. Once that happens, he will be gone.

The sad thing is they believe that these agreements are honored.