Doing a quick check on Etrailer I couldn't find any after market receivers that have a TW rating of more than 750lbs.
Theoretically the recommended minimum TW is 10%. Max is 15%. You're around 13% now. You could lower the TW to 12% and be within you receivers rating. Or an after market one with a 750lb rating. JMO but 1% won't change the fact that you're getting some sway (push-pull) from semis. Normal IMO with a setup like yours.
About all you could do to get home would be max the PSI out on both the Durango and TT tires. Drop the TT coupler down another notch. Or if the TT's level now then leave as is. Remove some TW to be okay with the receivers rating. Make sure you have the correct weight transfer to the front of the Durango. That can be done by measuring. You should return the front to the recommended height after hitching. Drive slower. Not saying you're going too fast, but try and keep the speeds at a comfortable pace.
