Most likely possibility without any major symptoms in your case could be a panic or
anxiety disorder that you have faced during last event and currently experiencing. Cause of such panic disorder mostly remain unknown but in this disorder you may feel symptoms like shaking, shortness of breath, feeling of choking, pain in the chest, nausea, stomach ache, feeling dizzy, tingling or numbness, chills /hot flashes, bounding heartbeat or fast heart rate, sweating etc.