Complex sentence: He has come to the realization, too late to change things, that everything was done in vain, that everything has been pointless, that he will even die dishonoured and disgraced for his well-intentioned actions.
Split into simpler sentences: He has come to the realization, too late to change things, that everything was done in vain. That everything has been pointless and that he will even die dishonoured and disgraced for his well-intentioned actions.