weigh on mind
weigh on (one's) mind
To cause someone a lot of worry, concern, or anxiety, especially for a long period of time. I know that money issues have been weighing on his mind ever since the company began issuing pay cuts. I really acted like a jerk on Friday night, and it has weighed on my mind all weekend long.
weigh on someone's mind
Fig. [for something] to be in a person's thoughts; [for something] to be bothering someone's thinking. This problem has been weighing on my mind for many days now. I hate to have things weighing on my mind. I can't sleep when I'm worried.