Two star Draugr can pack a big hit. Was it one of those?

Only recently started the Swamp myself and had a similar hit on my first visit there. After that I sailed around the Swamp biome until I spotted a Sunken Crypt reasonably near the shore line and, after sleeping and prepping up, I headed straight for that to get enough iron to craft better gear (iron mace 1st for me). That made progress doable for me, lol.

Keep going. The unlocks triggered by the Swamp are well worth persevering for... imho :)