Ford Repair: lincoln stalling, 2 quarts, high mileage

Question
I hope you can help me.  My lincoln (1997) town car doesn't want to go into gear when I put my foot on the gas. It hesitates and then it jumps.  Also, while driving along it will automatically shift down in gears. The transmission oil is good but the oil was 2 quarts low.  Could this have damaged my transmission?  
Thank you for any help.

Answer
yes it could have damaged it if driven very long like that-you didn't mention the miles if it is high mileage its even more likely
but not necessarily so-first is it full now-where is the fluid leaking from-have you had it serviced that will make sure fluid is clean and not burnt also it will give someone a chance to look inside pan for clutch material or metal which might give more insight into the condition of the transmission i might get blasted for this but i recommend an independant repair facility with a good reputation or a dealer instead of a chain store and i will leave it at that.