Scout around the edges of the swamps for slightly glowing yellow flowers. That will give you turnip seeds, plant them, expand them and use a few to upgrade your cauldron. When you get a decent supply move to the next tier food.

After that farm some leeches for the next tier healing meads and farm some draugr for entrails for the next upgraded food. Then you'll be ready to handle the crypts. Get enough iron for a better buckler and your weapon of choice then you can farm abominations for the swamp themed armor or you can run more crypts for iron armor.

If you are getting more than a couple draugr at a time during the day there is a body pile nearby. Back away, kill the dragur swarm and then sneak around until you find the body pile and use your bow from outside draugr perception range to take out the body pile.

Make sure you drink poison resist meads before you go into the swamps. That makes the damage from leeches trivial and pretty much makes you immune to blobs and oozers.

I've never seen a "puddle" in a crypt. There are flooded corridors that you have to swim through but crypts are all on the same level which is different from burial chambers. There should be a way out of your puddle unless you ran into a game bug.