No, I'm not from Sweden, but I have been learning Swedish since 2006 in anticipation of moving there in the future for a period of time.
I've pretty much had to listen to Swedish music, format my mobile phone and laptop to Swedish, and watch Swedish tv to try and get some kind of immersion. I use it every day and force myself to use phrases all them time.
I think it is great that your are going to Finland, Finnish is a challenge because it is not a Germanic or Romance language. Swedish could be a way in for you in Finland because it is 'the second domestic language' - and it is mandatory at schools, even graduates are expected to speak it to a good level. But I suppose Finns might see it as a bit imperial to speak Swedish as a total newcomer - and would prefer Finnish.
http://en.wikipedia.org/wiki/Mandatory_Swedish