I've hurt my elbow it's bruised badly now but only 2 days after I hurt it hospital says it's not broke but 4 days later the pain is unbearable?

Contusion. Bone contusions are quite painful. I'm sure you've been icing it. Sometimes a slight fracture can't be seen on an x-Ray. If the pain is worsening or not improving, see an orthopedic surgeon for diagnosis and treatment.