A lot of people go to work sick, with headaches (you didn't mention migraine which I experience as absolutely impossible to do anything with) with out sleep etc.

Personally, I go to work sleep deprived all the time. If I didn't, I wouldn't be able to keep a job. I often have headaches too. Migraines are the only thing that can put me out. But if you're getting by at work with missing so much and can live without the money lost, then you're able to rearrange your priorities.

You have priorities but, they might be in a diff order than your ex who prizes work.