That sounds awful. Glad you got through it. Don't know what you should do about sis issue. Can you schedule a counseling appointment in the future to help you break this logjam with him? The fact that you were scared you were going to tell him you were going to walk over the sis disrespect speaks volumes. It doesn't seem to be going away for you two as an issue. Seems like the lying, hiding cycle will continue. Also, he gets to turn you into evil Mum when it happens. Not sure what you should do to step out of this cycle but it sounds like you already know something will have to happen at some point.
Sorry you are feeling unappreciated after all your hard work this year. I hope everything works out for you two.