Yes, it is a very selfish act.

Imagine how must pain they must be in to act in this way, to dismiss or not realize how much harm they will cause.

Imagine how much pain they must be in to demonstrate such extreme selfishness. To behave in a way that seems so out of character, so different from how they'd treated their loved ones prior to that act.

And consider how selfless they must have been to have held off as long as they did. To have endured the immense pain and struggled to resist the escape of suicide, until that time when they were finally overcome and capitulated.