Well, I haven't been published, so my advice may mean nothing, but I think it can take that long sometimes. It doesn't have to be perfect the first time through, so you can always move on and come back to parts the are giving you problems. I wrote one that still needs to have edits done on it, and it took me five years to write the first draft. The thing is, it took me four and a half years to write the first 150 pages, but only six months to write the final 170. I didn't have a deadline so I just tried to have fun with it. If I had to do it again, I know that it would go much faster, now that the first attempt was out of the way. I learned a great deal just by writing the first one. If you are struggling with writing the first chapter, try outlining the whole story (if you haven't already). For me a good outline made things start moving much faster and more fluid. Hope it helps, sorry if it doesn't.
mwhahaha