This is a struggle I'm constantly living and dealing with every day.
The quick answer is, you have to prioritize and accept the fact that you will never be able to catch on all your tasks. There will always be something left behind at the end of the day, it's just impossible doing everything every day.
A book that helped me a lot is called Eat that Frog
I've been meaning to make a short video series on how to be productive and deal with multiple tasks per day, but obviously, I didn't find the time yet
I'll try to make it happen.