Same thing happened to me and a friend of mine when we first set foot in the swamps (We didn't go there intentionally though, we were just sailing around and accidentally "stumbled onto something new that seemed like fun to explore"). So we jump out of a boat, encounter a 2-star Draugr Archer who one-shots both of us. We then have to make a raft (no resources for another carve of course) and sail across the ocean to recover our bodies (no serpents encountered, blessed be Odin). Thankfully we did remember to bring a portal this time, because the draugr killed us on the spot again and was literally guarding our tombstones. Long story short - we managed to recover our stuff after several attempts, but we never got our revenge on the draugr :D and we also learned a lot in the process haha.
I guess the moral of this story is - while dying is annoying (talk about your lost skills) and can often be very inconvenient (having your stuff stranded on another island), it also teaches you about the game and how NOT to die. In the end, however many times you die - it is still fun to explore :) so don't let a small setback discourage you.