Falling out of love with the perfect guy?

I've been with my boyfriend for almost 2 years and he's absolutely wonderful, everything a girl would want in a guy, would be a wonderful husband, father and provider.. He hasn't done anything wrong but I feel like I'm falling out of love with him, the passion that was there at the beginning of the relationship is gone. Is he just not the right one for me or is that just how love progresses? The passion turns into stability and just having someone? I don't know if I should break up with him and let him go, or if I'll regret it after finding out love isn't like it is in fairytales.