My family member is completely unable to understand my mental issues, and our Personality variations cause unneeded issues. Please assist.?

Okay. Here's the gist, I had to move back to my high school home. Life did not work out well. I'm rebuilding it. 

I'm a super introvert. Super type B. And have bad PTSD, with many function inhibiting symptoms. Big history of mental issues before the events that caused PTSD.

She is hyper emotional, big type A, huge extrovert. Been working since she's been 14. High functioning. No mental issues. Very hard worker, tough as hell. 

She loves me. And likewise. But she always blows up at me, randomly, for just my nature, or my PTSD symptoms in which I struggle with.

In the car today, I was highstrung. Fighting off dissociation, and controlling my thoughts. She patted my shoulder, and I flinched. Involuntary reaction. I wasn't alerted to her even about to.

She took it deadly personally. Yelled how I'm selfish. How "people like me don't know how they hurt people", how her boyfriend (who's also a big introvert) doesn't get it. Etc. WONT listen to the fact I didn't mean it in anyway.

I then got mad myself. Woman's 68 years old. And acts like a child. And look, I struggle to get through a DAY, and be productive. I could NEVER do what she does. Or has. But hell. We are NOT the same type of person. And lord knows my flaws are myriad.

I'm slowly getting more Pi**ed off. I can not make my mental crap go away. I get mad at myself daily for my struggles to do basic crap.

And then, to deal with her extroverted neediness, when I'm trying to focus on something.

Idfk .