this. Age is just a number but abuse is more common with age gaps and this is absolutely abusive whether OP’s girlfriend is 56 or 26. She’s taught him that age makes her smarter than him and in charge of him. This is a textbook abusive relationship

ANY fight that results in a hospital visit is worth ending a relationship over. It doesn’t matter here what you all were fighting over or how she’s made you feel (although her actions all scream abuse in general). She intentionally injured you. Run.