Welcome to Viking (not quite) Hel...

Each Biome approximately redoubles difficulty (Well not mountain that's about 1.3 x swamp at best)

Rule of thumb max upgrade gear and weapons of preceding Biome is Just about OK for limited forays into the next one :)

Swamp is a nasty Rubicon to cross so its not just you.
1) Have poison resists handy ditto healign meads
2) Scout first !
3) The Hoe is your friend
4) Rested Buff at all times or forget it
5+ Nah wouldn't wanna spoil it

Good luck!