You acknowledge that you are not experienced at towing by your reliance on others to to advise you....including the salesman.
You acknowledge you have made an error in the selection of TT.
Are you about to make a worse mistake yet by putting yourself, your family and the traveling public at risk of serious bodily harm or possible death?
Its not just a matter whether the truck can pull something it really is a matter if the operator and truck can control its load under all highway situations....
Is it going to be worth the risk?