Weird Behaviour is driving us to distraction

[RoxyKitten]

Hello fellow MC lovers,

Roxy has started displaying some really weird behaviour recently and we don't know what to do about it. Starting around the beginning of January, she now loves to sit on the headrest of the sofa behind us and pull really hard on our hair, also doing a sort of combing moting with the paws and claws.
Initially we thought that she was grooming us as a sign of affection, but it's really painful and we'd rather she didn't. So whenever she does it now, we try to stroke her and gently direct her away from our hair. However, if we do this, she gets VERY angry and aggressive and starts to bite our heads/hands quite forcefully. Not sure what to do about it - if we let her do it as she wants it's so painful to us, but obviously we don't want to offend her and teach her that we don't want her affection. Also unsure why she has started thinking this is a good idea.

Has anybody else encountered this behaviour and how did you cope with it/discourage it? Any advice would be welcome!