inxiety
To be so nervous that you can't sleep for long periods of time.
Jacob's inxiety about the test caused him to be tired and cranky.
iNxiety
An overwhelming feeling of nakedness, fear or anxiety when one's iPhone, iPad or other Apple device runs out of battery, or is lost or forgotten somewhere.
I nearly had an iNxiety attack when I thought I left my iPhone in the cab... fortunately, it had been my jacket pocket the whole time.