Stop psychoanalyzing her and keep your ducks in a row. That’s how you manage your stress. If you’re sleep deprived, correct it. Get adequate sleep. You need it.
Do the dishes before you get sleepy, and keep the bathroom looking sharp. We all have dishes and bathrooms and so will you, so get good at doing your chores.
Don’t worry about what your sister does/doesn’t do. If there is a disparity in responsibilities between you and her, make your mother aware you believe that. Tell her your opinion, but not of her parenting. Your opinion matters; it doesn’t override hers.
She has her reasons for keeping an eye on you. Discuss them with her so that she knows you understand them,
and ask her for whatever liberties you want.
When you’re on your own, supporting yourself, you can do what you want. Until then, cooperate with her.