Sounds like you've got a serious transmission problem. This is likely going to be a costly repair -- if your car is in poor shape or its value is less than the cost of a replacement/rebuild it may be better to just buy or lease a new car.
ita ford im not dogging em but they have issue with the automatic transmissions i drive a 2000 windstar for work and the trans went out at about 130000 my boss paid like 2 grand to get it redone if you have a hook up you may be able to get it done cheaper.