EXCLUSIVE

The wife of ex-NFL quarterback Erik Kramer told police her husband snapped and physically abused her on June 13 ... and now she's afraid he's a on a "manhunt" to end her life.

Kramer -- who played in the NFL from '87 to '99 -- was arrested at his home in Agoura Hills, CA on June 13. His wife immediately got an emergency restraining order, but now she's looking to extend it.

In her petition, Cortney Baird says she and Kramer had gotten into a verbal altercation the previous evening and she approached him the next morning to talk it out.

But, Cortney says Kramer flipped out and began cussing her out, pushing her around the home and then started grabbing various household items to throw at her ... including ice packs and their knife block. He missed on all attempts.

Kramer then allegedly started grabbing other items around the home -- glasses, candle holders, picture frames -- and started smashing them on the ground.

Cortney says she called 911 ... and cops raced to the scene and arrested Kramer who admitted getting physical, according to the police report obtained by TMZ Sports.

Kramer was booked at a nearby station, but released the next day -- and Cortney says she's in fear for her life and worried Erik could also come after her daughter.

In fact, Cortney points to Erik's 2015 failed suicide attempt -- when he survived a self-inflicted gunshot wound to the head.

Cortney says the incident proves Erik has access to guns and isn't afraid to pull the trigger.

"I am terrified that he is out looking for me at this very moment and will kill me and my daughter."

Cortney's request for a restraining order was granted -- Erik must stay 100 yards away at all times and has been ordered to move out of the family home.