1. Too much to do.
It's incredibly stressful to have too many things to do. The only way out is fight to keep you head above water and push through, or to recalibrate, reset expectations, accept defeat and start fresh.
2. Believing there's too much to do.
We may actually have too much to do. But more often, if I take the time to discover, I find that I just believe that there's too much to do. And once I give myself the time to sit down and get it all out of my head, it's not as insurmountable of a mountain as my imagination was making it out to be.