"On particularly rough days when I'm sure I can't possibly endure, I like to remind myself that my track record for getting thru bad days so far is 100%."
Its easy to let a set back crash you. Some times the tiniest thing seems insurmountable with all the other things going on in your life. Its OK to fall apart some times. We are designed to crash and burn... but don't set up camp and live in the crater.
We all have bad days, crashes, failures, and so on... but its like my 8 year old told me with roller blades..."Dad, when you fall you just have to get back up and keep trying." That's the key to any new thing, get up one more time then you fall.
When we were just babies, we wanted so bad to walk. We would crawl around licking stuff, and trying to pull our selves up. We didn't even know why we wanted to walk or that walking was even a thing. We just wanted to get moving. And move we did, across the floor, over the toys and into every sort of crash and trouble we could. Bruised and crying we pressed on. We never even consider that we could just give up. The thought never crossed our minds. Just the thought of, "What does that thing over there taste like?" We wanted to be mobile at all costs. Soon we got to our feet and took those first steps... and fell. Not just a stumble but a full face plant. But we got back up and kept going... and going... and going until now we may not even give a thought to walking. You did it! You got up one more time then you fell. You are a successful walker!
Now apply that to your current challenge, whatever that might be. Get up again, take another shot at it. And if you fail, try again... don't ever stop trying. Keep moving, you will figure it out.