I've lost my best friend and I'm pretty devastated. She met a new guy about 3 years ago and he's turned her around, she's a totally different person. I don't know enough to say he's controlling but if I had to put a bet on it I would say she is being controlled to an extent. There's loads of examples.
The worst part is he regularly treats her badly. I know he's done it again but she's not talking to me about it. I made the mistake recently of asking her if she was being controlled by him and she hit the roof. Since then she's gone really distant with me, only making contact occasionally.
She has always been a bit manipulative and is the 'Alpha' friend if that makes sense. But I've always gone along with it as she was very important to me. She's made contact to say she's in a mess and doesn't know how to get out of it, but won't answer the phone or tell me what the problem is. She most recently told me she'll make contact when she has the headspace. I'm 100% certain the problem is with the boyfriend.
TBH I have my own mental health struggles and her current mind games are testing me.