Im in love with a close friend?

I've known her for 21 years, and she's always been on my mind. We're both married and divorced, and both scared. We've recently reconnected and had a wonderful night, and what has been my infatuation for the 21 years, has turned out to be nothing less than...I cant even explain it. I'm sick to my stomach all day, my heart aches, and there isn't a second that goes by that she's not on my mind. She said that our night was perfect, but she's scared because of the hurt she's felt. We're texting every day, but the last thing I want to do is scare her away. She IS a little complicated, so I'm afraid the wrong words will make her run again. Do I pursue? How do I pursue? I want nothing else in this world but her. I've told her that we will be friends first, then hopefully when she's ready, maybe more. But it's killing me not telling her how I feel. We work different hours, so seeing each other is limited. Even when our schedules coincide, I don't want to seem too forward. Please help.