After your 9/10 hour work day, focus on something unrelated: Exercise, meal preparation - things you have already mentioned. Come back to your projects after a couple of hours, and WITHOUT pressuring yourself to do so. The added pressure will make these personal projects/goals less palatable.
I agree with this completely. I would like to add that if you are working 9-10 hours a day, you might want to look for a job that offers you a standard 8 hour work day. If you are passionate about side work, sometimes trading less pay for standard work hours is worth it.
After your 9/10 hour work day, focus on something unrelated: Exercise, meal preparation - things you have already mentioned. Come back to your projects after a couple of hours, and WITHOUT pressuring yourself to do so. The added pressure will make these personal projects/goals less palatable.
Edit: Clarity