I agree with
@billyS ..
I think she most certainly did you a favor-
How old were you at the time ?
Was she of similiar age..?
Don’t beat yourself for being naive and stupid.. You appeared to genuinely have feelings for her while she let you believe this —
At some point she obviously felt guilt and shame for misleading you and probably felt some shame, but did not know how to break your heart
I think many of us over their the years have similar stories