Suicide if undertaken for the right reasons is not an evil in Stoicism. Socrates committed suicide, Seneca also. However, if it’s merely a means of escape from your obligations and trials, it’s not virtuous.

Seneca wrote “The wise man will live as long as he ought, not as long as he can.”

But if your life has ripened, like a fruit, and is best at this moment, then plucking it is reasonable. Or if continued existence would destroy your moral or rational nature, a sagacious person might undertake it.

Epictetus: “The door is always open.”

That being said, most folks are not in that position, and if someone is troubled and suicide is a thought they are entertaining, then they should probably ask for help, as we would be obligated to give it as we were able.  We do not know under what pain he was living, and it’s difficult to “armchair quarterback” his decision.  We can look at the context, and the social roles he had.  His children are adults, his family secure.  He did excellent work, and he struggled (not always, but sometimes successfully) with his demons and flaws.