What key is this song in?

I'm composing a piano piece and want to write it down as sheet music. I don't know a lot of music theory and can't figure out what key this song is in. I have no idea if I'm correct but I guess that it starts in F# minor and switches to C minor? 

Sounds more like B minor

How did you write this down? I really like the sound, but it would be hard to nail down a key center because it is not all diatonic. 

18 minutes ago, wesleymiller said:

How did you write this down? I really like the sound, but it would be hard to nail down a key center because it is not all diatonic. 

 

I played it by ear. According to the DAW I'm using it's D Major but that doesn't seem right.

I would say B minor, while borrowing some things from Bb

From what I hear it centers around triads: Bmin - Gmaj - D#min

Later moving to Fmin and settling on Bb