Guilt is a very intensive emotion that can destroy lives. But it shouldn't be this way. The destruction starts when you don't accept it and don't want to understand what happened. Your resistance and avoidance is what creates destruction.
While it may feel exhausting and intense, the best thing you can do is revisit the incident, relive it, and pay close attention to what happened and your feelings. Accept everything. Analyze it. Find the fear that exploits you. You are stronger than that.