I keep hearing about waterproof claytors and mine is definitely not, I have two and they are both breathable ripstop. I use a thermarest, however I do not inflate it, I leave the valve open. It really helps and allows the hammock to conform to me more.
I also wonder if your hang is too tight. I find that when I hang too tight, my pad travels more and I get more "shoulder squeeze." I am not familiar with your climate, but I do know that if you have waterproof material I would guess with some certainty you are getting a lot of condensate. We lose a lot of water over the course of a night through our breath (tarp condensate) and through our skin. (hammock condensate)
I try really hard to convince my ground dweller clients when I take groups on canoe trips to leave the windows of their tents unzipped so they will not have that clammy wet feeling when they get up. More often than not they think they will be "warm" with everything tight as a drum. When it gets below 40, they literally get rained on from the inside of the tent fly because of the condensation. Dry on the outside, wet on the inside. I just love the way mother nature teaches.