blackbird-TA

fore the last few months. when ever i whoud be driving my car hard for just a short time the shiifter whoud lock up on me not letinng me out of aney gear.. iwhoud have to start the car and turn it off 3/4 times and shake the shifter a few times till it will let me in the gears and when i whoud try to force it in you whoud here a very weird nois coming from the tranny. whoud coud this be and how much will it cost me to fix it. (and yes its a M6) and if it helps you knowing what the problem is my clutch is sliping to but only when i race it..