You could either use two UTHs, both controlled with a thermostat, or you could increase the temperature of the room to around 75*.
A reptile thermostat is something you absolutely need to use with a UTH. They are hard to find in stores so you will probably have to order online. The reptitemp 500r is the cheapest thermostat that is reliable. I would order one of those ASAP.
You never said what you are measuring temps with, but if it isn't digital, then it isn't accurate.