94 Jetta GL tranny problems?

Im trying to figure out if my transmission is having serious problems. Occasionally, when I just start my car and I try to accelerate, its like my car can't get over 3000 rpms. And if I take my foot off the gas a little after trying to accelerate, I can feel a definite choking feeling, like my car does not wantto accelerate that much. Also, occasionally when Im driving, the car will randomly over rev going up to as many as 4000 rpm when Im not even driving that fast or accelerating that much. Because of this problem, Im nervous about changing out my transmission fluid because someone told me this might cause additional problems. Anyone know what this may be. Also, Im not a car person so I might not be as clear as I want to be. Feel free to ask me to clarify. Thanks

Can you get over 3000 RPM's while in park? The other part sounds like the trans is slipping. Changine the fluid now probably won't make any difference. You might want to be sure the fluid isn't low though.

As far as the revs go.... Don't overlook a clogged Catalytic converter.