Two words: Vicious Blows...
Only thing that helps here i tell you :P
Get a hammer, and smash them before they get a chance to smash you.
Oh, and if you haven't increased your mouse sensitivity yet, do so. It helps, a lot.
Actually, spinning your weapon mindlessy doesn't really help, "Run-up" blows are
much better, and offer you more control. Stay at a moderate distance, wait for
your weapon to get the right position (3/4 of a full spin), and then do a mighty
swing in the face of your enemy...