PLEASE NOTE: ALL APPLIANCES SUCH AS HUMIDIFIERS, REFRIGERATORS, FREEZERS, TREADMILLS, AND SIMILAR ITEMS SHOULD HAVE THERE OWN CIRCUIT. THESE ITEMS SHOULD NOT BE PLUGGED INTO THE GENERAL PURPOSE OUTLETS. THE MANUALS FOR THESE ITEMS TYPICALLY RECOMMEND DEDICATED CIRCUITS AS WELL
If the GFI is not resetting: Unplug any items that it may be protecting and attempt to reset it again. If it holds then you have an issue with one of the items you had plugged in.
If it still doesn’t reset, make sure it has power (circuit breaker/switch is on) try again. If it still doesn’t reset consult a professional.