Your symptoms probably are indicative of Tricep tendonitis. Skull crushers and overhead extensions put a great deal of strain on the triceps tendon and create an enviroment ripe for microtrauma. Generally takes a long time to heal and will be reinjured with these exercises if healing time isn't given. I would take a little time off all tri work, ice, stretch, massage the area then gently reintroduce pressdowns, CGBP etc...I wouldn't do any overhead extensions for a few weeks or skull chrushers. When you do start these exercises, begin lightly. Stretch out your tris prior to any activity.