Writer's block is the bane of us creative types! 

I had a professor once tell me that writer's block didn't exist and that I should keep writing no matter what, but I don't believe the solution is that simple. I think there's an in-between with it. I think you should keep writing despite the writer's block just to keep your mind rolling with some ideas, even if you think they're messy. Take small breaks, but never 100% detach yourself from what you're working on. Having friends to spitball ideas at also helps a lot. Always remember what may seem stupid to you may seem great to others. Music is also a god-sent for coming up with ideas.