Your numbers make no sense.
Empty weight (no trailer), is wrong, unless you have about 1500lbs in the bed of the truck, over the rear axle, but not forward enough to load the front axle at all. You may have a bunch of "stuff" in the truck bed, but that's alot of weight, like filled level full of firewood or a half yard of landscape rock, heavy.
Second weight, there's no way that adding the trailer takes over 400lbs off the front if it only adds 300lbs to the rear axle.
And you're purporting that the trailer only has about 300lbs tongue weight. That is virtually impossible unless it's the worst designed TT in history. Which it isn't, as every Salem Hemi TT near the size of yours lists >1000lb tongue weight, so unless you literally added at least 1000lbs to the back bumper of the trailer, you wouldn't get a 300lb tongue weight.
And if it does only have 300lbs tongue weight or something lighter than 1000lbs, why are you even using a wdh? That is making it worse.
Or, on the contrary, "if" that low tongue weight is correct, take the 900lbs of extras stuff the wife loaded in the back of the trailer out, or if not the case, take it back and tell the dealer they sold you an un-towable trailer.
Now, gut check time. Do you know the difference between dropping 300lbs and 1000+ lbs on the back hitch of the truck? 300lbs and the truck might squat 1/4" or something, and your tongue jack will run like theres no weight on it. 1000lbs, you will see and feel. Truck will sag a couple inches maybe more.