crutch
noun
°A device to assist in motion as a cane, especially one that provides support under the arm to reduce weight on a leg.
"He walked on crutches for a month until the cast was removed from his leg."
°Something that supports, often used negatively to indicate that it is not needed and causes an unhealthful dependency; a prop.
"Alcohol became a crutch to help him through the long nights; eventually it killed him."