Would you be willing to share your strategy? There were a couple times where I just didn't turn something in, even if it was half done. I'm in my late 30's now

Would you be willing to share your strategy? There were a couple times where I just didn't turn something in, even if it was half done. I'm in my late 30's now and still struggle with motivation. I'll go back and forth between 8-10 hours of heads down coding in a day to maybe 30 minutes. I don't think it's burnout because I honestly can't even tell what kind of day it's going to be until it's half over.