I had a nice home growing up and I was also depressed a lot in my teens. It's natural, and maybe from her perspective she is right, but your feelings are definitely valid and you have to work through them.
If she is a good Mom, try to understand that she's not trying to hurt you with her words, but once people get out of our teens we tend to forget how tumultuous the teenage years are and can be dismissive because by then we all see that things were not as bad as we perceive them.
For now, you be you and you keep talking about your problems. It's healthy and like I said, valid.