a millstone about (one's) neck
An extremely difficult or disadvantageous burden or hindrance. I wish I hadn't bought that house—the mortgage has been nothing but a millstone about my neck. Given the man's laundry list of scandals, he's proving to be quite a millstone about the candidate's neck.
millstone about one's neck
a continual burden or handicap. This huge and expensive house is a millstone about my neck. Bill's inability to control his temper is a millstone about his neck.