Overextending yourself is when you say yes to too many things and cannot follow through on them. This is a very bad situation for a writer, especially if the goal is publishing. When someone puts a deadline on something, take that seriously. Yes, life happens, but if you are complaining about not having your work done and you are bragging about binge-watching a series on your favorite streaming service...yeah, that's not adding up and you did not overextend yourself. You opted out of the responsibility and work in favor of something fun, relaxing, and not work. This happens a lot and at some point to all of us. When I have fallen victim to the procrastination monster, it has resulted in some very late nights and early mornings. It's miserable and it teaches me a lesson...until the next time, but that is usually a decent distance in between those events.
Here is where those handy dandy leadership traits and principles I learned in the Marine Corps come in. Know yourself and seek self-improvement. If you know you need more time, don't push yourself to get three things done on a deadline you are being optimistic about meeting. Just say no. It is okay to say, this is not going to work for me. I can't meet that deadline.
The other side of that is pushing yourself. Ask the real question here, am I overextending or am I pushing? Pushing means you have three manuscripts that are 80-90% done and you have not finished them, yet. You sign up for something as a means of pushing yourself to get those done. This is what I am doing for 2022-2023. I went through my partially or completed stories and said, you are putting the ones you have done out and you are going to finish the ones you do not have done and put those out, too. If I am waiting on me, it will continue to sit there. If other people are counting on me to have my ish in order, I will finish it. Some of us can push ourselves. Some have to be pushed by others. Some, are like me, somewhere in-between.
Now, take a breath. Ask yourself, am I overextending myself or am I pushing?