I’m getting destroyed in Irithyll

I’m level 39 and i have a Sharp Lothric Knight Sword Plus 6, and 24 dex. I’m getting basically two shot by every enemy and the second more than one comes at me at a time it’s basically over. Could someone maybe tell me what i’m doing wrong? The earlier sections of the game weren’t nearly as difficult and I feel like I missed a section. I tried to go to the Old Demon King but i figured that he is also for a much later level.