The ‘nice’ times are not nice - they are an intrinsic part of the abuse cycle. They are a grooming and manipulation tactic to reel you back in after an assault (verbal, emotional or physical).
I am astounded at PP on this thread saying give him an ultimatum, sit down and talk to him, record what he does etc.
No.
He actively chooses to abuse you each and every time. He now has you in a perpetual state of hyper alert walking on eggshells adapting your behaviors and thinking (“wrong” potatoes?!?!?) 24/7/365.
Your physiology will be swimming with cortisol and adrenaline, your heart will be racing as your base state. You won’t be able to think straight as your body will always be in physical trauma mode - poised for fright, flight, fight, freeze, fawn or flop. You will be exhausted and erode as a physically and mentally.
Sunlight is the best disinfectant. Tell some trusted friends - tell them you need support to get out. That will start the ball rolling.
You don’t need to minimise or JADE (justify, argue, defend or explain) your actions and feelings to any of his family and friends.
You can have one line “He is relentlessly emotionally violent to me” - rinse and repeat. No need to give further details. You don’t need their approval or owe them an explanation. Expect them to be shocked or disbelieve (or deny - some will already know) and just turn your back and disconnect.
Emotionally detach in your head.
Know that no one deserves this.
Know that it is over and you need to get out swiftly and cleanly.