Stam should never be a Problem. You can easily regenerate by just kiting Mobs via Walking. 1 or 2 Star Draugr with Bows are the real Problem, so try killing them from Distance with a Bow. Anything else you just let come to you, wait for them to strike, then parry and finish them off.

Shield and Poison Potion are important, as is good food. 2x Health and 1 Stam.

Never run into the Mobs and start swinging, because then they 100% get their hits in. Always isolate, parry, then combo finish. Make sure you are rested too. Valheim is all about preparation.