op - i'm a new mner but an old hat with the 'cutting' issue.
ds1 is also 14. at the moment he's been brainwashed and kidnapped living with my estranged and barmy mother.
the sad fact is tough love cannot work in this situation. also, do not expect miracles from health proffs either. unless your ds is stealing, violent to others, or taking hard drugs, there's very little they can do.
i also feel that the self-harm issue is a confusing area.
i have done a hell of a lot of research into this, and my experience is, majority of self-harm is done in secret, and then hidden. this new way of harming self seems more like a weapon, or a way to manipulate parents etc so that dc can get their own way.
this doesn't make it any less upsetting for the family, and also, for the child - their emotions are still just as valid.
one positive i've taken from this, was that when ds1 got his own way (living at bitch from hell mothers), the self-harm has stopped.
i realise that this is no help to you in current situation. i also have dts age five, and that was impossible to police. ds1 would be delightful to them when he felt like it, and then horrendous for no apparant reason.
my advice is take a step back. and that's crap i know 