1995 grand cherokee

Did this problem just happen out of the blue, or has it been building up little-by-little? You don't indicate your type of transmission - Manual, Automatic 3 speed, Automatic 4 speed - So I'm going with the assumption it's an automatic. Beyond the Fluid and Filter change, there's not a lot that many DIY's can do to repair especially with the fact that the engine computer also controls some transmission functions. If you haven't had the Fluid/Filter changed, or checked your fluid level, go ahead and do so, especially if you're not sure when/if it's ever been done. If it HAS been changed fairly recently, sounds like a trip to the shop. Hopefully it's just fluid/filter...