There have been some very helpful replies already so I'm just going to add this:

Imagine if your kids came to you and told you they were depressed (if you don't have kids, imagine you do and you love them very much).

Then imagine that -of all the things you could possibly say to them- you chose to tell them what your mother told you.

How would you feel about yourself as a parent (or even as a human being) if you did that? Essentially calling your own children worthless for being sick?

It's ok to feel that same way about your mother.