I Am Always Go Gym And Work 5 Days A

I am always go gym and work 5 days a week as a groundworker apprentice I'm only 17 and after training last Wednesday I woke up and could not straighten my arm it is not the pain or discomfort present stopping me from straightening it however it does hurt I'm worried and confused as to what it could be pain is mainly present where golfers elbow causes pain however I haven't heard of not physically being able to straighten it due to that