definitely try to take a trip to Sweden and practice the language with the natives! Ideally, you should make your stint at least a few weeks if not more.... if you're single, you could always try to find yourself a swedish partner...
I myself moved to a spanish speaking country a year ago to do my PhD without any prior knowledge of the language.... After a couple of months, I started getting a handle on spanish and now I'd say I'm pretty fluent (mind you, I make plenty of grammatical mistakes since my only formal training is a 2 month's beginner's course!!). My native tongue is french, which certainly has helped a lot!!
Good luck!!