Yes, I know that one very well, @deedds. I don't call it "hell" lightly. And it affects you physically, too, because you'll be running high cortisol and adrenaline levels. The strange thing is that your body gets used to these levels, and so while it feels awful, it is also somewhat of a chemical dependency. So it becomes a vicious circle.
But, you see, writing about how awful your feeling doesn't change it. Does it?
You need to do something. Of course, the first thing you'll want to do is to contact him. That will give you the psychological and chemical fix you want. But it will also just keep things going - cycling, cycling, cycling. And you find out that you're still in hell.
What you could do, is do something different: book yourself some therapy (not counselling; it won't help, imo). There are therapists who offer reduced fees if you ask. And don't be afraid to ask.
It's one step, then another, then another. It can feel thankless at times. And then one day, if you keep at it, you'll look back, and realise you're somewhere different. And you feel different. And life is different.
Either that, or just keep choosing the same-same.