Dig yourself a hole - Idioms by The Free Dictionary
dig yourself a hole
dig (oneself) in(to) a hole
To get oneself into a difficult, undesirable, or disadvantageous position. Boy, I really dug myself into a hole by procrastinating on this paper until the last minute.
dig yourself (into) a ˈhole get yourself into a bad situation that it will be very difficult to get out of: When I started lying to him, I realized that I was digging myself into a hole which would be very difficult to get out of.