You could just run into the crypts with the swamp key. You should be fine fighting the stuff in the crypts. I did that aswell, first boss buff helps immensly getting through the swamps... I gotta admit it is hard at night. But perfectly doable without fighting a single mob.

It's easy to get overwhelmed there. But I'm also confused as hell by your comments saying how less dmg you do. I did 3 crypts full with draugr with upgraded bronze mace only. And they are dead within 3-4 hits.

Poison attacks from blobs are nasty tho.