My friend borrowed money for treatment and lied about being ill

Dear Delyara, My friend told me she had cancer and needed help paying for treatment her insurance would not fully cover. I transferred £4,000, organised a fundraiser, and asked other friends to contribute. Last week, her sister contacted me. There is no cancer. My friend has gambling debts. She invented appointments, scanned fake letters, and once shaved part of her hair before meeting me. I cannot understand that detail. I sat beside her crying because I thought chemotherapy was taking her hair, while she knew exactly what she had done in the bathroom beforehand. She has admitted everything and entered treatment for gambling addiction. People keep reminding me addiction creates terrible deception. I know. I want her to recover. I also feel violated by every moment of tenderness she manufactured inside me. I drove her to an appointment that never existed and waited outside for two hours because she said I was the only person she trusted. I am no longer sure which friendship I am grieving: the one before the lie, or the one I thought we had while she was pretending to die.