...interest and it's clear she? is a lesbian, but I heard her mention to this other girl that she is seeing this "sweet boy named Adam" now and doesn't need to be set up on dates (the other girl was trying to set her up on a date). I'm so confused by this girl; she is so attracted to me (I can see it in her eyes) and she gets so nervous around me, yet at other times eagerly shows me signs of interest, but now I hear she has a guy she is seeing. WTF.
Sort of heartbroken here! This girl at work is always showing me strong signs of...
Romance her. steal her back 
Maybe she doesn't want to take the leap and is playing if safe...or she's toying with you. Just muster up the courage to confront her in an earnest way that you're interested in her and ask her if she feels the same about you. Don't leave things hanging, so the conversation should end with a conclusion. Either she is willing to go with you and only you, or move on and find someone better.