I think I remember you from another thread.
Can't you see that his infidelity was just the tip of the iceberg here? And his contemptuous behaviour post-affair is a further layer of that iceberg?
Unless you contradict me, I bet your husband has always been a selfish, sexist and controlling man.
The reason you're depressed is because you stay with him and hate yourself for doing so.
And because you realise that you've put up with this for years, but didn't cotton on to what he was really like because you assumed his fidelity meant he loved you.
Having the affair wasn't the crisis point you seem to think. The first time you put up with his selfishness, was the watershed moment in your relationship. That paved the way for more of the same from him. Of course the person with most responsibility for that is him but it's also true that it's human nature to test boundaries. A selfish person pushes them though - and if they don't get called on it, they'll just get more selfish and entitled.
My advice is stop making this all about the affair, because it is only significant in that it should have been your watershed moment, that finally gave you proof that you were married to a selfish, sexist and entitled man.
You need to find out why it wasn't and why you've continued to enable his behaviour. That would be helpful to you as an individual.
But you are flogging a horse that died years ago, if indeed it was ever alive in the first place.
Your depression is because you're still with him, suffering the effects of his behaviour and suffering the effects of your own contempt for yourself for allowing it.