Sounds like advanced stage of type 1 pneumonia. Your animal needs a CONSTANT warm area,the heat pad is probally your best bet. If its on a thermostat and keeps turning off and on all the time it probally will soon develop in to type 2 pneumonia, thats when the real trouble starts.Try conecting the heat pad to a ligth dimmer and set it so there is a constant warm spot to lie on.Pneumonia in reptiles is almost always caused by stress, wrong temps are one of the first things to stress the animal out enough, but even when kept at right temps things like handling to much, being kept in high taffic areas,ie living rooms etc can cause pneumonia.Once a reptile gets pneumonia it will have it for life, it can be kept at bay by de-stressing, but will always reapear when stressed.
Rob