1995 BMW M3 Strange Clutch Problem

The other day I drove home from work in a flash-flood. Turning on my street I found myself in several feet of standing water, but had no trouble driving through it as it was only about 5 feet in diameter. (I didn't know it was that deep or I would have gone another route). Nothing seemed to be wrong with my car but the next day I started it without a problem but couldn't get into gear. I had the clutch (which has never had any problems previously or even had much wear despite the high mileage) completely pressed down but I couldn't even shove it into gear. When the car is turned off, though, it goes into gear fine. If I try starting the car with it already in gear it acts as though the clutch is not depressed and leaps forward into a stall. I've tried all the gears and none will work, even several days after drying out. I'm just praying it's something I can fix myself, please tell me what can be done without pricey mechanics - I'm still in school and have enough problems paying bills as it is. Thanks for your help!