I love wild camping but am plagued with bouts of lower back pain, mainly from the Sacroiliac joint. I have tried a variety of sleeping mats over the years but never seem to get it quite right. My most recent purchase is a Thermarest Neoair X Lite. It is only 170g, warm and is fairly thick to give some cushioning. It wasn't cheap at about 130 quid. Only issue is that it is too narrow (I'm no Kate Moss) and slippy so I keep ending up on the floor. Woke up in Corrour bothy 2 nights ago on the hard wooden floor in serious pain

I had thought a hammock would be good but you can't always find trees to hang it on and it would make me anxious not knowing I can pitch it anywhere.
Anyone got any mat recommendations for the feeble-backed amongst us? I appreciate I will have to compromise on weight but the lighter the better really.