"My biggest enemy is me
And even I can't stop me"
"You Can't Stop Me" by Andy Mineo
Full disclosure, this is a Christian artist and there's some Christian imagery. I'm currently more agnostic leaning, but this song still gets me pumped up to face anything I find intimidating. I once listened to it 5x in a row at full volume while bouncing around like a mad woman to build up the courage to switch out the shut off valves under the kitchen sink (plumbing is my nemesis).