so that could be another reason your snake doesn't like the warm side: an unregulated heating pad can easily reach 120° F+ when left running and those temps can kill your snake. please unplug it when you get the chance. also, that heating pad should have gone underneath the enclosure to provide belly heat for digestion; a UTH (under tank heater) does nothing for ambient (air) temps.
all heat sources need to be regulated. so you have a UTH and 2 bulbs: that means you need 3 electronic controls to regulate them. i recommend you read up on the differences between a rheostat and a thermostat and judge what will work best for you and your equipment.
i suggest you read through this stickied thread: how to set up a glass enclosure. the photos are down but this link here has all the photos from the OP so you can follow along.
if you can swing the Herpstat EZ2 then go for it. i absolutely LOVE Herpstats and they will likely last for the snake's lifetime. if you go this route just remember you have 3 heating elements so you would need 3 electronic controls.