My mom is...?

The first thing you need to do is accept the fact that you can't make her feel better. It isn't your job. My mother suffered depression, still does, and I'm 45 years old. We spent most of our life tip-toeing around her and trying to find ways to please her and make her laugh. I ended up feeling resentment at one point in my life. Let her know you love her and help out at home all you can. But do not spend your days feeling responsible for her happiness. Remember, she is the adult and you are the child.