I know it's so hard to pretend to be cheerful when we're soo low. It takes so much energy. It's nice that you are still so considerate towards your family. They probably have no idea how hard it is for you. It seems a common thing for depressed people to pretend everything is alright. I know that I do it all the time.
I've never had therapy but that seems kinda strange for a therapist to say. I'd talk to another professional and just see if what she said is consistent with common practice. Also does that mean you only have 5 sessions left? Not fair!
Just know that we are here for you and understand a lot of what you are going through.
I hope you feel better.