I don't want to depend on my girlfriend's mom's schedule
Do you think you can make a compromise with the schedule?
No, but I'm going to stay with her anyway.
It's great that you all live together like that, but you still need to be independent since you're getting older. It's not good to keep wanting people to take care of you like a child. It's creepy, and a strain on the adults.
I guess it's time to grow up.
Everyone has to become an adult eventually and this sounds like a good opportunity to experience that growth. Branch out from your comfort zone and get on your own schedule. It may be tough at first, but the freedom you'll experience is worth it.