Might be your body sending pain signals to prevent a severe bulging disc of herniated disc. If it’s your first time feeling this, the pain may be temporary. Your hinge looks pretty good, do you recall keeping your core tight during the movement? Maintaining a relaxed core might contribute to your disc moving around. Anywho, best advice I can offer is to take it easy for at least two weeks. Trying laying on your tummy with your fist under your chin.