When I look up "slight personality," I get Borderline Personality Disorder.

I couldn't find much about U.K. laws, but I was trying to see if there is a statute of limitations for medical things like this (e.g., "medical malpractice"). Apparently, there is no such thing in the U.K.; it is only a U.S. thing. However, if you get a personal injury from a doctor or there was medical negligence (it wasn't clear if it included "mental injuries," though), you have 3 years to make a claim and that's it. Same with many other types of legal claims. So going off the 3 years thing... idk if that nurse could even get charged with anything. It'd likely be too late even if you had actually wanted to press charges...? (I know you don't want to press charges. I'm just saying you probably couldn't even press charges if you wanted to.)

See here:
How much time do I have to make a claim for Medical Negligence or Personal injury and what is the “Limitation Period” - Lexology

So as far as getting that nurse in trouble goes, it sounds like it's not even possible, unless the hospital themselves wants to take it up with her. But even then, she could argue that there is only 3 years for the patient to make a claim, and since you did not make a claim, she may feel she cannot get in trouble.

I'm not saying you should or shouldn't get her in trouble. But I just don't think it's even humanly possible to do it at this point since it's been 8 years, if that's what you're worried about.