Is it time?

Where is the line that says you can finally give up? When is it okay to just stop believing, because maybe what everyone has been saying is absolutely right? I think we all have these moments in our life where we say ok this is more than I can bear, but yet we press on. But like, isn't there a line where it actually does kill you. And the truth is it is not an honorable death. It's like you are pressing on like you are some martyr, but the truth is it's suicide. When is enough really enough?