If it’s Monday and you feel already like you’re struggling, it may be time to hit the reset button and ask why.
One reason may be you have too high expectations of what you can accomplish. If so, I recommend you read this: It’s Okay to Be Good and Not Great
Another reason may be that you just don’t have any energy/vigor/gas in the tank/what have you to get things done. If so, then start with this:
Building Healthy Habits When You’re Truly Exhausted
Finally, if you’re not sure what the problem is, but you think you suck for some strange reason, then go through this fine collection of articles to see if any of them can help: You’re Not So Bad: The Case Against Self Improvement
We don’t have to be at our best all of the time. Sometimes we are at our worst or close to it. These things come and go like clouds. Be good to yourself. Take a moment for yourself. Then do what you can.