If you have a long list of things to do, you need to cut some tasks out. Prioritize the ones that are the most important ones. If you have too many things to do, it'll overwhelmed you even more.
If you are tired, you have to take break to recharge. The more your work, the more burnout you'll be. Taking a break is good for the mind and body. Health should be a top priority.
There is always a system for everything. If writing down all your tasks helps you, then do it. Find a system that helps you be productive. Everyone is different so not everyone's system is the same.
Most people think that multi-tasking is the way to go. However, multi-tasking will hurt you more. If you do many things at once, you can't focus. Focus on one thing and finish it before moving on.