I’d also ask that you see if it’s not emotionally, mentall, willpower drained amplifying how tired you are. If you are drained of those things, I’ve found it’s best to push through. However, it’s ok to change your expectations.
If you’re trying to build a habit to work out…. The goal is to get into the gym regularly. The workout is important but if you keep but that happens after you get here. So simplify the goal of just doing one.
It’s like imagining if your goal is to do 20 push-ups, start with trying to something crazy simple such as 1 push up a day. Make it so small it’s super easy. The reps and the regularity are why build the habit. Eventually over time your pattern, habit, or muscle memory will kick in in spite of what you’re feeling.
I imagine we get more out of exercise when enjoying it, though!! Good luck and keep at it!!