So this may have been requested here before? But I'm kind of at a loss of what to do so I figured I'd ask the community.

The back story is long but I'll shorten it but as best I can.

So I recently moved to a new city largely due my brother starting university, largely for a good job I got, and largely for a girl I felt I truly had a chance with that I got involved with over the summer (believe me I know it was a mistake). She was very flirty over the summer and we were quite physical when we were around each other. Fast forward to when we moved and all of this had slowly fallen off and at one point I asked her "what's this going on here? You know how I feel about you so I would like to know how you feel about me" short of it: She's very attracted to me but she doesn't want to date right now and she likes what we have going on (see: this summer) but by the same token she doesn't even know what she wants. Okay cool, at least now I know what's going on and I can live with that.

Tonight we hung out in a large group setting and she was next to a guy she's been hanging out with a lot and there is clearly something there so in my head I've lost the battle and now I need to move on. But how? I want to block her on everything and never talk to her again for me own sanity at least until I get my shit sorted out and I don't feel what I do for her. I feel this is immature but on the other hand I feel it's foolish to drag myself like this and still try to be her friend while she's getting more and more involved with this other guy. I just want some kind of advice on how to do this with some level of grace and dignity. Any help appreciated