possible tranny problem

right now my 94 gp is messing up during "intense" driving for a while my overdrive gear quits working and i am cruising at 65 at 3500 ish rpm instead of 2000 whats wrong and should i be worried about it?

the computer could be seeing overheated fluid and locking you out of 4th for a while. So in other words dont be so hard on it

is there any way to fix it?

If its anything else other than the trans trying to protect its self from overheating yes if not no

ok thanks