He's a very cruel, sadistic man. What does HE sound like, passed out on the couch? Probably a pig.
Maybe you should leave some cinderblocks on the floor around him and turn off all the lights. See how he likes stumbling around in the dark when he wakes up!
Be sure you mention the fact that he has a gun to the policewoman when you call her.
If this continues to drag out, I'd talk to the dog trainer and get your male dog back. You can put him back in training once this person is gone. Explain to the trainers what's going on (creepy abusive a$$ is threatening and hitting you) and I'm POSITIVE they would agree you need the dog home NOW.
And keep your phone close.
Prayers and thoughts for you and your son.