First point: You need more Ambusher. Your adventurer is only mortal, no matter how buffed he gets. One good hoof or arrow to the brain and he is done, period. The best way you can avoid this scenario for as long as possible is ensuring that you never get attacked, instead cutting the enemy into little chunks without them noticing. I always train to Legendary +5 Ambusher before trying to kill anything even modestly dangerous. At that point you can stand right next to it and slash away and almost everything short of a Megabeast won't notice.
Second, your start build doesn't really make any sense. Recuperation is useless, because as soon as you Fast Travel anything that will heal will heal. Presto chango, just like that. Disease resistance is also extremely pointless, as the only thing it does right now is prevent you getting vampirism or lycanthropy, and that only happens at insane levels of Disease Resistance, and the attribute is effectively impossible to train. Those two attributes should be your dump stats, not at Superior. For the rest, you don't really need Endurance, and you should always max Strength, Agility, and Willpower. Strength and Agility are vital to any adventurer, as having them start high means you can cap at many times the abilities of a standard creature. Willpower is hard to train, but is crucial if you want to live long. The moment you chip a bone you have a very high chance of giving in to the pain, and the moment you do that you are dead, for all intents and purposes. Thus, you really need Willpower to survive for long without savescumming often.
As for skills, you really only need Novice Swimmer, as swimming is easy to train in any murky pool. Just don't train in temperate areas close to night. Armor User is a really nifty skill to have, but again you can train it very easily by letting an undead groundhog try to hurt you with any decent armor on. You don't need to start it that high, put the points into Observor and your chosen weapon profession instead. Observer only trains when you get ambushed, and directly increases how far away you can see said ambushes and how often they happen. Thusly it is quite difficult to train without dying, as ambushes are a great menace to the low-level Observer/Adventurer.
Finally, you should be doing well otherwise. I can't emphasize the need to train Ambusher enough. It's not sporting in the least, but even with Legendary Dodger, Armor User, and Shield User, some lucky goblin archer is fully capable of putting a silver bolt through your brain. The best solution is to rip him limb from limb without his friends even noticing their buddy being eviscerated right next to them.