Reverse stalling and momentary RPM drops

I Have a 1990 Jeep Cherokee Limited with about 125,000 miles. I have two problems: first one occurs while driving, every so often when I hit a ditch in the highway that jolts the car the RPM's will drop for a quick second and then return to normal. On my 30 mile commute it will occur many times but not every time.

The second issue started all of the sudden, when I try to go into reverse the car will buck and kick erratically. Initially it would stay running but now it has progressed and will stall once shifted into reverse.

Any ideas would be greatly appreciated.