I don't believe it's too far at all. But that's just my opinion.
Yes, of course, you continue to work on yourself, try to improve yourself, make yourself more attractive.
But you can forget trying to have conversations, send cards, do nice things. When they are in the throes of the enorphin rush, they are best left alone.
Furthermore, as long as she is involved with another, she should get NOTHING from you. No contact, no coming over, nothing.
Involvement with another means you get none of me.
Obviously there are different opinions. Your job is to choose what you think will work in your case.
Bill
"Don't tell me the sky is the limit when there are footprints on the moon."