2000 Honda accord CEL and Mat Required light came on, car started shuddering

Is the CEL light flashing constantly? If so, stop driving. Your car stuttering is probably massive amounts of misfires going on. And if you keep driving, you'll end up damaging the catalytic converter. If you must drive, go slow, and I wouldn't go further than 1 mile. Get to the nearest mechanic to get the car scanned. Hopefully it's your spark plugs gone bad or one of your ignition coils. Easy fix on both of these. First and foremost, get your car scanned with OBD reader, rent one from a friend if you can.