heverhoney
It's great that having a child has made you feel so happy and fulfilled (even at 2am when changing nappies?). However, the reason for your life is many things and she is just one of them (albeit a big one).
I don't want to sound gloomy but, in my experience, mothers who wrap their entire lives around their children and see the kids as the reason for their existence do tend to have a harder time as the children get older and need them less.
The reasons you give your life (you, not destiny) include family, friends, work, holidays, the things you learn, the things you share, the way you grow as a person for your own sake.
Keeping a balance between them is really important both for you and for what you can give to your child. You are yourself first and a mother second.
Of course, you may still be in the rosy glow of post-birth hormones and do enjoy them while they last.