I've got a '94 GTS and last night after I started driving, I couldn't go from 3rd into 4th. Then after trying to accelerate from the lights, I noticed that I couldn't go into 2nd either. I don't think its my clutch because I have no problem with 1st, 3rd, or 5th. Reverse is also though but still goes in. Only the bottom gears. What's my problem?