My topspin serve is LITERALLY diving into the net. It starts off with a very high arc when it comes off my racquet. Then it turns kamakaze on me and takes a nose dive. Checked my toss. Over my head. Checked my contact point. Slightly, but not excessively, lower than my first serve. Checked my racquet head speed. Swinging through as fast as I can. Ive been playing for 2 and a half years self taught, On my highschool varsity team, so I have no idea whats wrong at this point. HELP? If critisizm requires a video, Ill try to get a video as soon as I can.