Freshwater or salt water?
Perhaps try a free race sail (vs your RS:S race sail) and see if you don't get some better bottom end.
Larger (approx. 9.0 m2) free race sail might help, but in a true 12-14 knots I'd think a "gruntier" 8.5 m2 would do the trick.
Are you moving back on the board "progressively"?
Some of the Futuras are kinda sensitive to where/when you move back on them.
Too soon, they don't want to plane, not far enough, they don't want to plane, too far or too fast and they realy don't want to plane.
A little larger fin (due to your 95 Kg. weight ) might work. Do you have a 36 cm Lessacher Duo?
Hope this helps,