I tell my kids that motivation is like a muscle. You have to build it up. If you start with just a tiny bit, that is okay. But if you don’t actively work at making it grow, you lose even that little bit. So, it’s okay if you’re not motivated to clean your whole room today. Just think of ONE part that will make your life better. Maybe clear off your desk so you can do your homework. Then be conscious about how the accomplishment feels. See if one more little part seems like it would feel that way. Maybe make your bed. Now, half your room is clean. How does THAT feel? How does the other half feel?
Anyway you get my drift. The room gets clean. Because once you start accomplishing, it seems more trouble to not deal with the (doable) things you haven’t accomplished and have them weighing on you than to just dig in and make them happen.