Wait or give up?

I have a coworker that I really like. I've liked her since the minute I saw her. I just wanted to see if she likes me, and I'm not very good at telling that. She dresses better on days that I'm at work. We always have this little flirty chat about how tough each others' job is. She seemed upset the other day, so I checked up on her that night, and she said she greatly appreciated it. And, last but not least, I have low self-esteem. It's getting better, but she thought maybe we should wait to go on a date until it's better. Should I go ahead and wait, or should I give up?