Many of us have a hard time sitting down to write due to many of life's distractions: the dog needs to be petted, the cat needs your leg as a scratching post, the kids are always hungry, and those dishes won't do themselves. Add this to the fact that your boss is on your back about doing some work, and there's no time for writing.
The truth of the matter is, if we want to write that book, essay, poem, article...whatever, we have to plant our butt in the chair and do it. We have to commit to ourselves that this is more important than the dishes.
Decide here and now that you will write everyday for 30 days. Then from there, decide that you will write for an hour or two, or you will write 500, 1000 words. Do whatever is doable for you. Not only will you create a habit of writing everyday, but you will have written something!
Now, you might say, what if I can't think of anything to write?
What I do when I am blocked and can't think of anything to say, I start writing about how I can't think of anything to say and that anything I put on paper is crap. This works like a charm. It clears out all the garbage and gets the writing process flowing.
As a writer, it's important to commit yourself to your writing. For me, writing is very important and it's time I treated it the way it should be treated....like a priceless gem. Good luck to you!