If he was as sick as everything indicates, the thought of outing it all behind him undoubtedly appealed to him. I doubt he had any other way out. Still, he had to be enabled.
I don't know what deals he may or may not have been offered. Our criminal justice system is so entwined with the "rights" of the accused. Sidney Powell suggests it was not suicide (at least that is what I read from her post/implications.