OP, you did not handle yourself well with this girl. You missed the important cues and went off/got angry over little inconsequential things. So your frame is crap (gotta be honest).
That screams out to a woman that you are behaviorally unstable. Given her history with behaviorally unstable guys, this would be disconcerting for her. Hence the shjt tests. Women need to feel SAFE before anything else. You failed in that.
Her wanting communcation from you is not unreasonable. Nobody wants to feel ignored. She's not asking for hour long phone conversations, she wants to feel like you give a crap. A quick touch base like "Hope your day is going well
". She's obviously attractive and attractive women ALWAYS have options. Always. There will be other attractive men who want a shot with her. You missed yours.
She liked YOU but you were a jerk and acted in a terribly socially uncalibrated way. She has a troubled history, but she probably tried to be supportive of her ex (and trust me none of us here know the details of what happened the night her ex killed his cousin - he might have shot his mouth off & said something ugly about her or the guy's kid - the cousin might have acted threatening to him or his family - you have no idea the context). We don't know. We can't know. Everyone is capable of killing another person under certain circumstances......
This girl cannot predict everything around her. None of us can. Who would think something like that could happen between family members. Geez.
His behavior is not her fault, and that man is still her kid's father, so it's complicated.
But that isn't the issue here. The issue is YOUR behavior. You do not have the frame you think you do.
Read up on leadership. Great leaders do not sweat the small stuff. Great leaders are trusted by people they lead. Great leaders are not jumping up and down saying "I'M THE LEADER! YOU ARE SUPPOSED TO FOLLOW ME....."
That's acting like a petchulant child. She already has a kid. She has to parent that kid. She should not also have to parent you.
It's done, she lost respect based on your behavior. Go take stock in the mirror and do better next time. This goose is cooked.