As was mentioned, go cold turkey.
You don't want to find out who she's with now. It'll just piss you off, and make it harder to move on.
Oh, and next time, don't do all that extra stuff like flowers/gifts/etc..., unless that's just how you are. If you're doing it to impress her, or keep her around, just don't. If she needs that stuff to be interested in the relationship, all it's doing is buying you a little time till something comes along that's more interesting than flowers.