2002 Honda Civic It won't "go"

I have a 2002 Honda Civic with 38,000 miles on it (bought it used from owner). I've never had any kind of problem with it before this. When I push on the gas, the engine revs very high but hardly accelerates at all. If I keep my foot on the gas the car will eventually, but very slowing and with lots of loud reving noises, get up to 25mph. The engine check light came on shortly after this. I made it home, but just barely. Now the car won't move at all. I don't think it's a major transmission issue (fingers crossed) cause it has such low mileage and is in fairly good condition. What things can I check before taking it to a mechanic and having them tell me I need to replace the transmission?