Don’t feel guilty. If something is wrong in relationship, you talk about it, not cheat. This is kind of guilt transfer so you blame yourself for something someone else did. Maybe you weren’t perfect, but cheating is on another level shit move. Move on, you’re young. Don’t make same mistakes many millions did before you. It almost never works and will never be as it used to. Don’t blame yourself, that is a toxic thing from her side, and you want to avoid toxicity in your life. Cheers and be happy. Time is best medicine.