Bummer! Glad to hear everyone is okay. It does suck possibly losing a rig, but it can be replaced. I was in your shoes two months ago when mine was rear ended. I ended up coming out very well on the deal, even though they totaled my truck. Hopefully you can as well. Im assuming the other driver has insurance and they will take care of you. I lucked out and the adjuster from the other guys insurance was super helpful.
Since you mentioned it in the thread title, and a post, I'll throw in my $0.02. Right before settling with insurance on my claim I sent the adjuster an email stating all the mods, maintenance, and other stuff I had done to the car in the last 5k miles. Some stuff I could remove from the truck to reinstall on the next one, and others that I had pretty much just given to whoever would end up buying it from an insurance auction. I mentioned in the email that when I originally bought the truck it took several months of searching, a plane ticket to get it, plus fuel and hotel to get it home. All things I had known I would have to do, but now I was being forced into doing it again. Also reminded him that my truck was hit Oct 2, not looked at until Oct 21, and finally got a rental a rental on Nov 1 (because I had to ask for one, they never offered). I told him to get with management and let me know what they could offer me as compensation. My goal was to get an extra $500 out of the deal to help in buying the truck back. His response was he could not out right compensate me for anything, but could use the rental as a scape goat. He offered me $50 a day for the 30 days of being out a vehicle. Do the math and one good email scored me an extra $1,500 above and beyond the value of the truck. He and I also talked about these are somewhat rare vehicles. All the ones I had been finding as replacements were not close to home. Plus big 4x4 SUV's go up in price around winter time. Throughout the whole process I was very patient, reasonable, and willing to give a little here and there to make his job easier.
Mine is a 2000 with 198k miles in decent shape. Their offer was $11,500 for the truck, minus $3,000 if I wanted to buy it back or "owner retain" as they call it, plus the extra $1,500 from my email. I ended up buying mine back because all the damage was cosmetic, frame was still straight and it was still drivable, minus missing a rear window. The adjuster told me he thought I was making the right move buying it back. He said it might not get a salvage title even though they wrote it off as a total loss. Here in Texas the state gets a report from insurance about what happen. The state looks at the overall value of the vehicle, then determine the price of parts to fix it. If the parts don't add up to 80% of the vehicle value it will not get a salvage title. They don't factor labor or paint because those rates and prices vary from shop to show. It might vary by your state.
I hope your experience in the next coming days and weeks goes well. This was a first for me and luckily turned out to be a good experience overall. I have since bought a parts truck (or two) to fix mine with, then sell whats left of the parts donor to come out ahead. Yours looks like it might have more structural damage than mine, but it still has a ton of good parts!