Beat yourself up
Definition 1 of 1
Pro Tip 1/3Emotional Intensity
Indicates strong feelings of regret or guilt, often more than is reasonable. 
After losing the game, he was beating himself up all night.
Pro Tip 2/3Self-Reflection
Used when someone is dwelling on their own mistakes or shortcomings. 
She kept beating herself up for not speaking up during the meeting.
Pro Tip 3/3Informal Context
Common in casual conversation rather than formal or professional situations. 
I always beat myself up after eating too much junk food.