A few things helped me, I got married 6 months ago.
1) Go crazy with to-do lists. I literally had a to-do list for every day for the last 2 weeks, things that I needed to do each day (call and confirm caterer, make wedding programs, etc.). So if you wake up in the middle of the night, just add a note to the list and realize you can do it later. My fiance and I would look at the schedule every night to make sure we were on task and not forgetting anything.
2) Go ahead and start packing for the wedding day. I put a big box in my living room and started putting stuff for the wedding day in it. Votive candles for the reception, toasting flutes, etc. I wrote in a sharpie on the side of the box so I could see at a glance what I'd already packed.
3) Enlist your friends! I had 4 girls as helpers on the wedding day (2 handed out programs, 1 read scripture, 1 ran a video camera) and I assigned each of them something to be responsible for on the day. Florist, Caterer, Cake, etc. So that way they knew everything I did and no one had to pester me on the wedding day.
4) Like everyone else is saying, realize that the most important part of the day is getting married. I kept reminding myself that as long as I had the marriage license, the groom, and the minister nothing else really mattered!
Best of luck to you!