The past is the past. You can't erase, change or take back a single thing - not a gesture nor a few harsh words. The only thing that matters (now) is how you overcome what's happened to you and how you carry yourself as a person, as a human being, regardless of everything or anyone. The most complicated thing in this life is the human heart - it feels just about everything. So don't be bitter, don't hold on to anger, don't ruin another person's happiness - simply let go.