I'm guessing it feels like it's rigid down the middle, and "dips" on either side near the bottom (where you legs sit). Basically feels like you're laying on a curved edge and your legs are sort-of "hanging".
If you haven't already, get yourself some whoopie slings and remove
all of the stock webbing from DD. That stuff is horrible and you'll never get a stable pitch as long as you've got that crap on there. Get yourself a few meters of static climbing rope (or climber's webbing) and run that through the gathered ends... tie it off and connect the whoopies using karabiners.
Pitch the hammock and tension it up as far as it'll go. Lay in it for a moment (this is for "bedding in") and by "moment" I mean 5-10 mins.
Be sure to move about as much as you can during this time as it'll help bed things faster.
Now... loosen the pitch two inches on the foot end, and one inch on the head end... lay in it again for as long as you're comfortable (minimum of 5 mins). Keep loosening the whoopies by an inch or so on both ends (though ideally you want the head end higher than the foot end for comfort) and repeat testing it until it feels right.
To make comfort testing as accurate as possible, lay in it as though you're going to sleep (inside your sleeping bag etc).
Took me about an hour the first time I pitched to find my perfect setting... after a few uses in different places, I can now set the DD to that exact "butter zone" every single time, no matter how far apart the trees and no matter how high or low I pitch.
Practice makes perfect, mate... you just need the whoopies and better rope/webbing (that won't stretch) to get the amount of adjustment you need to find what works best for you