I cheated on my fiancee about a year ago with a friend. It was a one time thing. It took a lot and she forgave me. I proposed to her three weeks ago and she said yes, but I ruined everything. I invited the person I cheated with to the engagement party. I didn’t want her to feel bad and she was still my friend. When my fiancee saw her at the party, she threw her ring at me and left. Now she’s blocked me on all social media and has been unreachable since. I called her brother and he told me to forget about getting married to her after what I did. I had to cut off my friend. How do I fix this? I need help. I realise I made a grave mistake. I can’t replace her.