Okay. I'll be blunt. You are a textbook example of why self-diagnosis is bad. You blame all your social difficulties on ASD. And, fine, maybe you do have it, but are you aware that it runs in families? Because this:

In all of the things that I remember about my grandmother...I definitely see traits of narcissism in her as well. Abruptly cutting off on the telephone, an aloofness when the topic turns towards other people, and the topic always has to be (and this is between both grandma/mother) about THEM. If I were to bring up matters in my own life...for them it's subsequent and irrelevant..my feelings don't matter. It's like this narcissism has run rampant throughout 3 whole generations...and now my younger brother seems to have minor traits as well.

Yeah. This could very well be ASD. Not being empathetic and rambling about yourself, while not caring much about others is textbook ASD.

But really, that's not what's important. You need to stop looking for diagnoses for everyone. Stop putting people into good (ASD), Normal, and Bad (NPD) categories. It's seriously messed up to abuse psychiatry this way and it's definitely contributing to a social stigma against the mentally ill that you should find personally offensive.

Focus on you. If you think you have ASD, see a doctor. My sister has a severe form ASD, and her doctors have given her so many good strategies for living (and never any medicine, fyi).