What seems to be the problem with my '94 Toyota Celica?

It’s 15 years old?

Sounds as if one or more of the gears has gotten damaged. How does the transmission fluid look?

Some info on servicing the transmission can be found here.

Throwout bearing? Pilot bearing?

Your gears are very likely rubbing, I’d do a major check of the transmission fluid! If there is any friction at all they will get messed up fast! That can get ugly sooo quick!!! Take it to a trusted mechanic asap O_O – LB

Note: my boyfriend (a HUGE car nerd) is currently bouncing behind me in a mild state of panic! hehe

Thank you everyone for your help. My brother said it is likely a throwout bearing, but a different mechanic that I asked said that if it was the bearing, then all the gears would be unusuable. So I’m going to try to have a mechanic look at it this weekend. Again, thank you all for your help.

You can still shift with a bad throwout bearing. It’s the noise and the odor that are diagnostic.

@pdworkin Thanks. I hope this is all it is.

Well, but if you can’t get it into certain gears, you may need to replace the clutch. The clutch kit will come with a new throwout bearing. Take it to a less looney mechanic is my advice.

A throwout bearing will make the car hard to get into gear from a standstill. You can usually hear and feel a distinctive clunk if you get the thing into gear at all. I’m guessing low trans oil, like a lot of others here, and maybe your tranny is due for an overhaul. Or your car is ready for the big used car lot in the sky.

The ‘94 part.

Remove the radiator cap and drive a newer car under it.