if u dont have alchemy then buy the poisons, something that can either damage over time or maybe silence it so its forced to get close. this requires one swing.
use legdes, cliffs or whatever gives you a height advantage to jump on top of the dragon (in oblivion it was poosible to jump on top of ppl for a few seconds, so since its the same engine you could jump on the dragon and smack it... consider not using power attacks cus that might make u fall off.(save when ure on top if u need the practice...btw this is mostly for fun but it should be tried atleast once

get a companion
get a bow, because in the world of roleplaying, flying creatures have always been superior to "melee types" thats why magic and archery made sense to use in such cases.
if a dragon can be paralyzed, use that to your advantage.. if u want a background story why your hero can paralyze.. imagine your bulky muscles are so strong that your punches are legendary.. or something like that.