What is my boyfriend killed himself because i cheated?

I'm sorry to hear that. It's important to remember that suicide is a complex issue and there may have been many factors that contributed to your boyfriend's decision to take his own life. While your infidelity may have played a role in his decision, it's important to seek support from a mental health professional to process your emotions and feelings of guilt. It's also important to reach out for support from loved ones during this difficult time. Remember that suicide is not your fault and seeking professional help can be a helpful step in healing and moving forward.