You're not alone... :-) Some people live in Sweden for 50 years without learning or understanding it, whereas some grasp it within a couple of days.
Most of the "big western languages" like English, German, Spanish and French mainly stress 1 syllable in each word. Well - I'll try to explain it with that as a base of knowledge.
Let's use the English word "window" as an example. Normally it's pronounced with stress on the first syllable (WINdow). Try moving it to the last syllable (winDOW). What happens? Well - not much, but it feels odd and the "win" part of the word seems to be too short. Try making the "win" part slightly longer while keeping the stress on "dow" (wiinDOW). Wierd, and doesn't really work (but you need to try it to understand).
Now try thinking of "window" as the two words "win" and "doe". Imagine someone standing at an 19th century fair crying out "Win a doe", and think of what it would sound like from afar... "Win Doe". Try it a couple of times, and say it slightly faster each time. This is the word "window" with equal stress (i.e. not an English word anymore, but fairly close to the Norwegian "vindue" meaning the same thing).
Now try the same thing with the two words "kveenn" and "nah". Try making the 'ee' sound on the first word quick and the 'n' sound long. After a while you will end up saying the Swedish word "kvinna" with equal stress, just the way it's supposed to be.