Sleep apnea can cause insomnia, but so can a plethora of other things. Sleep apnea is when you stop breathing during sleep, either because of an obstruction in the esophagus or the brain fails to signal the muscles to breathe. I'm more inclined to believe your insomnia is due to anxiety, not sleep apnea. But, I'm not encouraging you to stop wearing the anti-sleep apnea dohickey until you talk to your doctor. Just to be safe... And there is the possibility that more than one condition can cause insomnia.

Do you have different doctor for your temporal lobe epilepsy? And, if so, have you told him/her about your insomnia?