If being straight and open with her will cause the ruination of your friendship, just think what keeping it to yourself and dropping it on her at the last minute will do.
True friendship will survive this, but it sounds like your friendship is somewhat based on whether the situation is suiting your friend or not.
If you feel that you have to move back to where you feel you belong, you have to do it and try to be as open and honest with her as possible. If your friendship goes down the drain, you can then be pretty satisfied that it wasn't because you were being secretive, sneaky or deceitful.
I'm sure there are other people in Sweden you can make friends with.