My Max did exactly the same thing - I was positive I was going to end up with a Mr Bigglesworth (Dr Evils cat!)
After 6 weeks of it - and I mean HUGE dense clumps coming out - I took her to a professional groomers and they literally blew the excess out with the highest power blower they had - didn't stop it totally but it was never as bad again and has only recently totally faded to normal - 3 months on.
It's worth a try though - it made a world of diffence though!!
Good luck!