The massive fight went down at the couple's L.A. home on the evening of June 11 ... when Brittney and Aaron Zalewski got into an argument. He had previously overheard a casting agent call her "babe" over the phone, and allegedly went ballistic.
In docs obtained by TMZ Sports ... LAPD says things got physical when they wrestled for her phone -- Zalewski noticed she was recording the argument, and during the struggle he threw Palmer, and she hit her head on a bedpost.
Brittney told cops Zalewski yelled, "Pack your f**king bags and go!" -- but wouldn't let her leave. She says he threw her down again -- pinning her face down on a mattress, with his knee in her back. She says she struggled to breathe for 2 minutes while he held her down.
And there's this -- Brittney says during the fight Zalewski scratched his own arms and yelled ... "Why are you making me do this? I just wanted you to love me."