^^^^ It'll only get worse now I'm afraid. Mine was slipping while on the rollers at R-Tech (Stage 2 though) so I knew my goose was cooked then.
Your best bet may be to contact Alex at AKS and see if he's still doing his Group Buy on the Helix clutch set up. Just under £1k fitted for a Helix clutch, new DMF and whatever else parts are needed (I wasn't paying attention) for fitting and labour. Its has a great pedal feel, only slightly heavier than stock and it inspires so much more confidence.