Check out this great summary of the book, "Six stages of Parenthood" by Ellen Galinsky. You're not alone. It's been happening over and over for millenia. The stages you go through as a parent are familiar, frightening and so much fun to prepare for when you know what's coming!
If you need some motivation and inspiration, check out Galinsky's ideas.
Remember: Keep it all in perspective...keep that top-level 'DAD' vision that is so necessary: