Hi and welcome to PC!

What did he find out about you that gave him such disappointment and crushed his image of you? I'm guessing he is very old fashioned and chauvinistic, and this has something to do with that.

I agree with GoldenWaves, in the fact he has gotten nasty means he is deep down an abusive guy and you did dodge a bullet.

I would have an honest talk with him about this and find closure. Whatever it is you did shouldn't warrant his nastiness.