Welcome to the Jayco forum. I had a similar experience a few year ago when we purchased our 2011 Jayco X18D Hybrid and towed it with my V6 4Runner (2006) I my case it was a 5000lbs towing capacity with a loaded TT maxing out at 4500lbs. Not a dangerous combination, but not ideal. WD hitch, an added tranny cooler, and staying out of the mountains gave me some added piece of mind, but I always knew I was "towing on the edge."
You will get lots of great technical advice on this forum from people that know about towing campers safely. It is up to you to decide what will work for you.
I believe that getting to where you are going is half the fun , whether it is your favorite CG 45 minutes away or your "bucket list" trip 2500 mile away to the Grand Canyon. Make it safe and make it stress free.
2008 Toyota Sequoia Limited
2011 Jay Feather X18D