I'd like to see a picture of the door jam sticker. Tow capacity is calculated by towing a flat trailer with weights on it - much different than a high walled TT. Payload will be reached/exceeded before stated tow capacity. Don't remember if you have a tow package, and I'd also be curious as to what kind of tires you have on the truck/how old.
I was also told (as a towing newbie) that my setup was "doable". That was mostly correct, but found out that I don't like "doable", and therefore am in the mkt for 2500/F250.
Good luck