Ok from the what i can tell of the picture, it seems that your water bowl is on the opposite side of the heat lamp. You need to move it to the middle and you need a bigger water bowl. Once in the middle, let you humidity settle then adjust the water bowl towards to raise humidity And away from the heat lamp to lower. Also what watt size heat bulb do you have in the heat lamp? You would probably would not want to go any higher that a 50 watt ans really,may need a 25 watt.
Here is a pic of my old 46 gal bow front aquarium that my pb was in. I work a 48 hour shift and so i had to figure out how to keep the humidity up without having to mist. To do so i got the big corner water bowl and it worked. I did however lose space as the bigger water bowl took up about a 3rd of the tank. I have a hide on the cold side and the hot side.

Also if you have a lowes or home depot near by, they have ir temp guns that you can use to check your temps. Last if you can see it in the pic, i have a acurite thermomter from walmart. It has a probe. Probe goes on hot side and the unit goes on cold side. It will give you the temp on each side and it also does humidity. $12 @ walmart.