You saw the signs, and now you're taking positive steps to remove yourself from a negative situation.
You're doing what you need to do.
I know it's difficult.
Appearances are very important to dysfunctional families. It's more important to keep up appearances than it is to actually fix things, in that unhealthy dynamic, because fixing things means admitting something's wrong, and nothing is allowed to be wrong.
Hence, she's very concerned about your opinion of her son, because you are a thread to keeping up that appearance, and she wants to build it up again. She doesn't want any cracks in their facade.
Just keep doing what you're doing, keep helping yourself, keep being polite but excusing yourself from the situation...
You're doing fine.
