Overwhelmed and worried about safety

You should be able to find a much lighter hybrid than what you mention. We used to have a Starcraft Antigua 195ck for example that only weighed 2700lbs dry and was 3800lbs loaded for our family of 4. It was 19’ when towed but opened up to 28’ and could sleep up to 8 people. Tons of room and storage. We towed it with an ‘04 Toyota 4Runner which is similar in size and ratings to your Grand Cherokee. It towed great and something of similar size/weight would easily be towed with what you have and be under your ratings.

As for the hitch, get something with built in sway control. Popular brands are Equil-i-zer, Blue Ox sway pro, and Reese dual cam.