Yup you have the death wiggle. Careful cause it will break your control arm brackets off. I had it really bad and have done alot of research on it. Cherokees are known for having problems with the death wobble. First things first.
Do you have an adjustable track bar? If so make sure it is A) tight. real tight. not just the bolts but the adjustment also B) make sure you check the adjustment with the vehicle on the ground. Not on a lift.
Next, Check your alignment. Pick a reference point on your tires, like a lug or sidewall. Then measure the distance between your front tires using that reference point. You need to measure the front of the tires then the back to see the difference. This is your alignment. If the difference is more then .5" then you need an alingment.
Next, Make sure your tire pressures are even. One front tire at 30 and the other at 35 can increase the chances of the wobble.
Next, Check your tie rod ends. If they have alot of play its time to replace them. If not then dont worry about them. They are not causing the problem.
Next, Spend some money on a good steering stabilizer. The problem with stabilizers is they dont actually cause or eliminate the problem just add a little more force to the issue to keep it from happening. That is until the shock starts going bad. Which by the way will be much sooner then it should.
Any questions just ask.