Hi Slammie, just wanted to lend my support as I don't have any advice for you - hope it gets better soon.
One thing I have been doing with my little perfectionist is watching things like gymnastics/ice skating etc which strives for perfection. Having her watch the athletes fall and get back up repeatedly will hopefully drill into her that even the elite make mistakes at the worst possible times and can recover. Maybe there is a way of increasing that message to your son through whatever his interests are? perhaps you could find a concert pianist making an error on you tube and carrying onto great applause. I wouldn't necessarily say why you are watching it but do point out how great it is the pianist kept going etc.
Our piano teacher also stressed the importance of playing easy pieces at the end of each practise to increase confidence after a challenging piece.
I certainly don't think that is a magic cure of course, but I think our kids seek out media that shows perfection and they get an unrealistic view of how things are. Just my 2 cents
