I use a 150 CHE bulb that is on a dimmer. Once my other herpstat comes in it will be on a thermostat as well. You can put a heat lamp on a dimmer but room temps can affect the ambient tempts so a dimmer might not always give the desired temps. Anything that is going to effect ambient temps will effect your humidity but you need to increase your temps, 65 is just too cold.
What are you using as substrate? I use Eco-earth with my terrarium to help with humidity.
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