I feel really bad. How to make it better?

Sit down and have a conversation with her immediately saying you are sorry for what you said and explain that you were under stress but it is in no way an excuse for your actions. Let her know all that you have told us. It is good to hear that you are loved and appreciated for all that you do. Let her know that you will clean like she asked and that you are sorry again. She will see that you love her and are truly sorry.