Cant understand languages I speak, feeling like I'm fading.

Lately over the past two years I've begun to notice that when people around me speak, even in english, it sounds to me like a garbled alien language. I'm having more and more difficulty understanding direct conversations, and my sense of self has gone away almost completely. I only feel safe and whole when I'm by myself in peace and quiet and I'm not sure what this is called or how to describe it, really. I'd like to get help. My environment becomes nothing but blank shapes sometimes and scary.