Sign #1: Forgetting Everything
Sure, there's preggo brain and mommy brain, but when you start forgetting things constantly, it's a sign you're burnt out.
When I had to move suddenly, I started forgetting things, which was so out of character for me. I also started losing things. It made sense, though: I lost my house and had to move suddenly, which was very stressful, and I was searching for a place on my own all among divorce proceedings. I was a burnt-out mom running on fumes. Realizing this allowed me to help myself.