Most Helpful Girl
Most Helpful Guy
1) You "smack her bit her" - whatever that means.
2) You slept with her friend and dumped her
3) You stalk her
4) She got the cops on you
5) She doesn't want to speak to you
6) She blocked you
7) She's engaged
You literally have NO chance with her whatsoever.
You haven't changed at all, don't kid yourself. You're extremely bitter and haven't moved on.
The guy she's ENGAGED to might not own his own home, might be older and not have a degree, but your ex certainly thinks he's the man for her.
I'd really recommend you move on and forget about her and start to figure yourself out before you start to date again.