The thing that works for me [which I know, everyone is different, but you can give it a whirl] is to sit in front of my computer, music to set the mood, then write one sentence. Just one. Make sure it's the first thing that comes to your mind. It seems to just keep flowing after that. I've also noticed that I write the most in the evening and at night...is there a time of day that works best for you?
I also have to write everyday whether I have writer's block or not, I'm just obsessive about that lol That also helps it not last so long, plus keeps your write goals on track.
I wish you the best of luck with getting unstuck, I know how bad a block can be :/
[sorry if this doesn't help, but I sure hope it does!]