Major General George Picket is best remembered for "Pickett's Charge," his disastrous assault on Union positions on Cemetery Ridge at Gettysburg. Years later, when asked why his charge failed, Pickett drawled, "Well, I always thought the Yankees had something to do with it.”
When we fail at life—and we will—Satan, the enemy of our souls, will have "had something to do with it." He influences our choices and exploits our weaknesses to corrupt and ruin us and, if it were possible, damn us all to hell.
There is no respite. Even old age is unsafe, calling for continual diligence, endurance and bravery. The battle will not end until we die and our Father takes us in. Only then can we rest.
We will fall in battle. You can count on it. "But it is the man or woman who gets up and fights again that is a true warrior... To feel sorry for oneself is totally inappropriate. Over such a soldier I would pour a bucket of icy water. I would drag him to his feet, kick him in the rear end, put his sword in his hand and shout, "Now fight!" (John White, The Fight).
So... you've fallen—again. Fess up and forget about it. God already has (Isaiah 43:25). Get up, patch yourself up, and press on. The Lord of Hosts is with you, fighting furiously for you. He has promised to guard your faith to the end and He will bring you safely home (1Peter 1:3-6).
The Confederate war effort never recovered militarily or psychologically from Pickett's defeat, but you can. In Christ, no failure is final. You're fighting a battle that's already won!