I struggled for years after dropping out with this, and still do to some extent. But came up with a crazy strategy to kind of get myself addicted to completing tasks on my To Do list. I think today I'm probably significantly more productive than the average person, but I never would have got to this level without going through years of pain and life destroying habits.
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.