I take the first step of reminding myself that I can't change anything in the past. But I can for the future. Bc I go through motivation lulls that really in the negative feedback loop like you're experiencing.
My method is multifaceted and I've come to it over trial and error. I don't expect it to work for everybody. I always say find what makes you flow because when things flow for you you always come back to it. Pomodoros are what keep me sane. I'm not a person who schedules every single part of my day. I tried it once I lasted 15 minutes LOL but I do find it helpful to say I will work on something for three pomodoros than to say I will work on something for 75 minutes. I give myself at most 5 tasks in a day to do not including habits. These are prioritized. This is a simplified view of my approach.
But I definitely want to encourage you to search for ways that people start their day using Google. Find a method that you might be interested in that you feel will help you relieve the stress of tackling the day ahead. Try it out for 2 weeks and if by the end of those two weeks you don't feel the flow don't keep trying to use it. I recommend looking for free templates as this is what I did I continue to utilize free templates even now. There have been times when I've hit that motivation lull but one thing has always been consistent I've come back to the pomodoro style with prioritizing tasks.
The template I use is from the productivity planner by intelligent change. I don't know if they still offer the free one week template but I've literally just been reprinting the same pages for years. Works great to help me feel like I'm staying on top of things without having this mile long list of stuff.