Here’s two quotes I really love:
This is a quote about having a goal you’re working towards:
“When things are hardest, a clear goal is the most important thing. To have a fountain of energy to draw from. Establishing a worthwhile goal is the hardest part. It gives you a place to go and a reason to get up.” – Earl Nightingale
This one is about building confidence, and that it comes from having a bunch of smaller experiences of success:
“Confidence is built upon an experience of success.”