Know the Difference

When all else fails... give it up!!

There is fine line between persistence and perseverance. Persistence is a continuation of an act after its cause is removed; Perseverance is a steady persistence of an action in spite of obstacles. These two attitudes are very much one and the same, but the strength with which they are acted upon marks the difference.

Persistence and Perseverance are virtues that can be so sincerely effected and nobly accepted. Just as Patience is a virtue, these two other P's represent a person's endurance. Through hell and high waters. BUT these virtues should never be overdone or exceeded.
Indeed, there is fine line.

Persistence can be annoying. Perseverance can be irritating.
When you've had enough (of anything, for this matter)... you've had enough. Do not over-indulge in the waves of its emotions. Up. Down. Bright. Dark. Happy. Sad.
When you say it is the last, then let it be the last. There is no such thing as "oh, by the way" or "and while I am at it" yada-yada-yada. There is no such thing as second to the last or last of all lasts. Last is final. Terminated. The end.

Here is the fine line. IF (not when) you see a ray of hope -- that one itty-bitty rarified streak of light that will be the culmination of all your actions -- then by all means, persist and persevere! But watch your steps as you do not want to detonate the bomb that will ruin all your efforts.
On the other hand, WHEN (not if ) there is nothing --absolutely nothing-- left to salvage any remnants, then stop there! For whatever you think, say, or do, will not alter or convince.
Give it up and move on. Don't look back. Don't even dwell on the "what if" or the "could have". Take it as a lesson learned.