Now things have changed, in work my first language is obviously Japanese since all my colleagues are Japanese, but I also frequently talk to people in English in the head office, with other foreign colleagues and at home with Ms. Sunshine. Also, in my years in consulting, English was the primary language. But the times I use Swedish are now pretty rare and usually limited to conversations with family and friends back home, speaking it is now problem at all if you exclude business lingo which I am not completely comfortable with in Swedish. But my writing in terms of spelling and grammars has worsened quite considerably.
So now I am in the situation where my Swedish level has decreased quite a bit, my English ability has increased and my Japanese ability has increased significantly, but as it looks now, I am by no means perfect in any of these languages. So now I've ended up in the strange situation of being semi-crappy in three languages, some form of balance has been struck and the three languages live in harmony and equality inside my head.
Maybe I should mention my German as well, once I had a basic grasp of German, but the Japanese took the German language in my head outside and gave it such a beating that it hasn't really dared to come back. I can still understand a bit, but the moment I try to speak, the Japanese shoves the German in my head to the side and out comes Japanese instead...
I do not intend to learn another language...