95' jetta auto not shifting properly revs high

Hi there - Just looking for some information about a problem I am having. My 95' jetta (2.0 engine - I think) needs to be serviced (is over 350km over the recommended service date) but I can't get it into my reliable mechanic for another week. Currently I am nervous driving it as it is not shifting properly and revs extrememly high when I have to acccelerate hard (merging on freeway etc.) It's getting up to 5 and not pickign up much speed. It is an automatic. I have had this problem starting in the last few days and it is quite noticeable driving both on the freeway and accelerating after a stop. It seems to cruise ok at 50 and if I let it ease into the speed, but as soon as I need to push a bit more on the gas it revs up way to much.

Any ideas about this? Someone told me the transmission may be gone! I hope not. Also is it worth taking it into a jiffy lube kind of place for a quick oil change to tide me over or not? I'm trying not to drive it too much currently.

I appreciate any comments. Thanks in advance.

the transmissions have alot of issues back then. Sounds like the transmission is slipping bad. I would reccomend a transmission filter and fluid change at a vw dealer. The transmission uses VW fluid NOT AFTERMARKET or dexron or mercon ect... It will cost about 350 usd to replace those but if that does not fix than you may need the transmission replaced.