Congratulations!

Offer to sign a prenup...she'll think it's noble of you. I can say that because I am a woman. It's not the size of the ring that matters either, it's the intention behind it.

Don't feel scared. I find it endearing that men get scared with the emotional aspects instead of other, more concrete things. You fly airplanes, you are ultimately responsible for people's lives. Believe me, you have plenty of courage to take the plunge and do well. I hope that she is a fine woman for you, and that you are a fine man for her