1998 Subaru Forester Shifter shudders violently

i have a 1998 Subaru Forrester. While starting from stop into the first gear or gearing down into first to come to a stop, my whole clutch (the shifter) shutters violently, and from under the vehicle you can hear a nocking or banging...only happens in first gear. If i hold the shifter very firmly i can reduce and almost eliminate the shuddering while driving, long enough to bring it to a garage i guess.