I had a really good friend when I was in my teens who had a boyfriend I’ll call Jack. The guy was a classic jerk, but she was crazy, CRAZY in love with him. Jack would do and say some of the most vile things to her, and she’d just take it. One time Jack slapped her right in front of his own mother. No matter what I said (I even begged) she wouldn’t leave the pig. What’s my point? I used that experience in my fiction. Sure, I changed a bunch of stuff, but the overall premise of a toxic relationship stayed.
Have you ever used personal experiences (whether your own, your friend’s or a family member’s) in your writing?