What Is Going On?

Simply ask her why she is so angry...if she goes pyscho on you then run... Seriously,her responce to to that question should detrimine your next step.
If you can't calmly discuss your problems,then it's not a healthy relationship.
And you'll have to ask yourself if you want to be with somebody who doesn't respect you and is always angry at you.
If she does tell you the why and it's reasonable then you can discuss solutions to the problem,but don't promise anything you can't or don't intend to follow through on.

Nah man it’s over. You forgot to read her mind and divine exactly which tiny little petty thing she took umbrage to. Mt CrazyGirlfriend will erupt at an hour most unknown.

Give her a greeting card that says, "I love us."

Ask her how you can help

She wanted you to chase her not not give a fuck. She didn’t stand her ground though.

You should have groveled on your break..

Take her to the doc?

you look her dead in the eye and say "Tell me what's going on or you'll have no right to complain"

Dump that b*tch

She's exacting her pound of flesh from you. Pay attention. There will be a quiz.