It's still normal. I've been in a series of long term relationships, and in all of them I experienced the same things. I have been with my boyfriend now for about 3 1/2 years, and after awhile it does loose that "spark". BUT, it should be replaced with something else. It's hard to explain, but it's more than just feeling comfortable with your bf. It's a deeper feeling of love. It's a bad sign if you start to become bored with your bf.
You just have to do things from time to time to spice it up. Do something different from the routine. Go hiking. Go to a nice restaurant, etc. My bf and I are the homey type as well, but we try to go out on occasion to keep things new and fresh.
I hope this helps ease your nerves a little. I know how much it can freak you out.