Step 2: Drink a large beer or whiskey on-the-rocks. Repeat until well-buzzed.
Step 3: Enter the plane and get yourself doing something to take your mind off of it, like music, movie, or book.
Cheaper alternative would be to get little sample shots from your local liquor store before you fly - those are allowed past security, and you can toss it in your orange juice while in-flight. Its a standard part of my carry-on now.
Benadryl will also work if booze isn't your thing.
The thing is, fear of flying is not a rational fear, which you already know. In my experience, irrational fears are best conquered by either chemical means, or embracing the fact that we can't always pick when we die, and for that reason you should always live life to the fullest. The chemicals also help with that idea.