I also have insomnia, had it for decades. I sleep about 3-4 hours and then I am awake for a few hours, then fight to get another 3 hours of sleep. Last night I slept in the tent and as usual I only got 3.5 hours of rest. Just the way it is. In a few days I will probably get an 8 hour rest period, then the cycle starts anew. In the meantime afternoon naps are a regular feature.
I picked up a inflatable sleep pad from Amazon by Trekology called the Aluf UL80. I'm 230 pounds and this inflatable pad works very well, and doesn't cost an arm and a leg. Comes with an inflation bag that takes 6 inflation cycles to fill the mat to firm. It isn't noisy like many are, and the weight is fine. Have zero issues with soreness and pressure spots. The biggest battle I have is a pillow. have yet to try an inflatable, but the foam pillow I made is near perfect.