Sorry to hear about it. But I warned you about that encounter. Warning is not enough though as that encounter is pure cheese and poor design. Really that is not your fault, that boss is inappropriate. you can beat it on second playthrough, in fact I beat him without his turn triggering ever, freeze and cc etc cheese tactics bs boss. Larian has a lot to learn in game design overall, albeit map drawing was done very well.
I moved away from this game, dropped it mid-game, loose of time, I am having a blast with DS3.
