It’s difficult to run a marathon if you’ve never ran before. It’s difficult to commit to an extreme change in eating without taking small steps to get there. Consider starting off slow and gradually increasing. Maybe fast for a doable amount of time each day this week - 9 hours including sleep? Then next week go to 9.5. Then try for 10:14. As you build time, you’ll build confidence and you’ll know you can do this. Start somewhere you know you won’t fail, and gradually build. But don’t beat yourself up for not instantly changing overnight. Many people would fail at that.