Of course I've said things in anger that I regret . Especially when I am tired. I am human.
he hadn't seen the food you had brought back for tea on the side and used that as an excuse to be mean towards you. he doesn't work right? so he has sat around all day, and when his servant gets home from the job that pays for the roof over his head he wants tea on the table instantly, and when it isn't and he rages about this, the servant has the cheek to answer back. Just can't get the staff these days can you?
You are not his slave, he is not a kid, he's not even a young adult, he's well into his 30s or 40s if I remember? I would stop cooking for him, don't do his laundry (I did my own laundry from when I was 13), anything else you do for him, etc. This is going to seem weird, but the arguing is something he wants too, so if you can, stop that as well.
From here it is easy to see how he has attempted to shift the focus, from his terrible, selfish, disrespectful, ungrateful, lazy, verbally abusive, arrogant behaviour, on to your exhausted flare up? And you've bought into it (I did too); instead of thinking "I wish I hadn't said those things, I'm tired and living in an intolerable atmosphere, I must make attempts to stop being so tired and to stop living with someone who i feel so horrible around", you're comparing yourself with violent criminals.
he needs to grow up, he appears to be far too comfortable continuing to be a toddler. I know you feel rotten about asking him to leave, but living together hasn't fostered any self-reliance and good behaviour has it? You have done your job, got him to 18, it is way past time for him to take responsibility for his own life, choices and mistakes rather than relying on you.
((hugs))