Is there a trick to beating the 2 Frost worms / icebound burrowers late game?

The ones after the blades on the way to the throne room. Just touching their bodies seems to one or two shot me. I haven't had issues with the difficulty of this game like some people (sure, some cheap deaths and those annoying rift things, but even the elden lord had the b.s. Holy laser thing) But this just seems like I'm missing something to avoid instant death, even lowering the stuff down to 70%. Oh, I was using daggers but did a bit of respec and tried longsword so I wouldn't need to get too close...but still doom... Thanks for any help!