What kind of story are you working on?

The biggest tip that I have in my arsenal that I can give you would to not get stuck in the mindset of what has to happen next must be written before what happens later. When I hit wb I find that writing an event that happens later will give me ideas of how to get there. But most of all, just have fun. If you don't enjoy writing it, it'll an empty pleasure people enjoy it without you.

Write lots, have fun, be respectful.
~SySheer

The only thing I can say is just write, to me, and most of the people I know there is no real way to get over it other then to just do it. You can always change it later when you have the ideas flowing again if you don't really like it right away.

Don't force it, you'll just drive yourself in circles like a mouse on a wheel. If you can't write because the creativity isn't flowing for one ficlet I would suggest setting it aside. I do this regularly whether I write or draw. It might take me longer to complete a ficlet or drawing piece but eventually a couple days later or even a week later I feel refreshed enough to tackle the piece again. You also have to be patient enough to let your brain breathe, you might just have a lot of other RL stuff on your mind that's blocking your writing juices. You could also be bored with your genre I like have been for a while with Inuyasha-verse, so I've written original stuff or written in another fandom and found that presto, I can write again.

Just give it a rest for a little bit is the best advice I can give. Making your brain do cartwheels when its not setting in gear to be helpfully creative will just make you cranky and annoyed 'cause you can't think of stuff to write. It happens to the best of us. Rest, a break, or just a good night's sleep can work wonders in your flagging creativity. Again don't try to force or rush writing, that will most definitely just add to your Writer's Block not alleviate it.

~ Pyre

P.S Stress is not good for the health btw, take a break, go for a walk, kick back and watch a movie. You'll feel better about it. I promise.

A while ago I hit writers block with Legacy of Hate and pretty much gave up on it. However, it kept kicking around in the back of my head and I decided that even if I didn't know the middle of the story exactly I knew how the ending would be so I wrote that. Eventually I filled in the middle.

Sometimes you just write the parts that you can see and come back for the rest.

Re-reading the material you've already written helps sometimes. It helps you remember the plot you were going with and may stir up some ideas to go with for down the line. Other than that, I agree with the others, take a break, don't force yourself, it usually only makes it worse.