So what would you do?

Exactly the same situation happened to me - we were co-workers (I can’t bring myself to do the cow thing); we stayed friendly and enjoyed each other’s company, but the worst thing I ever did was put my life on hold to see if she would ‘come round’. Of course she didn’t. To steal shamelessly from every other poster: move on.

BTW, there’s another thread somewhere about how rare it is for all dopers to agree on something - up to now there’s unanimity on this one - does this tell you something?

I get it. She doesn’t want to be with you AND doesn’t want you to be with somebody else! Sure.

Move on. Quickly.