Just one detail to add to the list of ancient texts indicating suicide as an option for Epicureans under extreme circumstances:
On his last day, Epicurus drank undiluted wine. With the dysentery he was in, this might have been suicide at least in the sense of accelerating the upcoming death.
There was a presentation with more details on this speculation that Epicurus himself might have committed suicide at one of the Epicurean symposia in Greece a few years ago, but I could not find it in my collection of references now.