I used to linger in bed like 14 hours per day. When I finally got out of bed, I would always have a headache from sleeping for too long but having it all be low quality sleep.

I just forbid myself to go back to sleep after my eyes open. I'm NOT ALLOWED. I guess pretend I'm in the military and there will be disciplinary action if I don't get up?
It's the same as establishing any other routine. It took discipline the first few times, but once it became a habit, it became automatic.

Also helps to have someone to report to for accountability. Pick a person and you have to tell this person every time you successfully or unsuccessfully dragged yourself out of bed.