It looks like you are growing it in partial shade. If that is a D. filiformis, it likes bright sun - the more the better. Low sunlight means little or no dew.
Humidity level does not affect dew production very much. Being in New York, yours probably never gets really low except in the winter, when it doesn't matter.
The plant seems to either be suffering, or has suffered aphid damage. Aphids are the usual cause of distorted leaves/stems - they love to nibble on young new growth.
