Throughout my junior year of high school, I had a recurring issue of demolishing opponents in the mid-game then screwing up so badly in the endgame that I lost or drew (I once lost an endgame straight up a knight). I faced a similar dilemma in the beginning of senior year, but I decided to devote my time on the endgame. Slowly, throughout the year, my endgame slowly improved.
In this game, I get wrecked in the mid-game and got saved by the endgame. Unfortunately, time trouble prevented me from holding the draw, but it was a strong confidence booster in my endgame abilities.