Don't feel too bad. When I bought my 2015, it only took 3 months for a 16 year old to cut a turn too short and hit a stop sign.
It took me months to sort things out with our insurance companies because they couldn't figure out fault. I raised hell until the other company took 100% fault. Do the same, it looks like you lawyered up, luckily I didn't have to, but be in contact with both insurance companies, state your intentions and threaten to sue the other driver. They will gladly fix your truck and take fault than have to pay out a settlement. A rear-end collision should be pretty cut and dry, regardless of what the police said.
Do yourself a favor. Go to your original dealer and use THEIR bodyshop for the repairs. Your truck is new, they will make sure it comes back looking new. I am meticulous about bodylines. If I can't tell my truck was in an accident, no one can.
Also, get a dash cam, front and rear, if you can afford. This is in all of my vehicles: