It seems that every time I go below 30 meters I get a throat squeeze. My personal best is about 37 meters and every time I go down past 22 or so meters I feel a need to swallow or I do swallow. The last time I dove to about 37 meters I came back up spitting up a lot of blood. What am I doing wrong????? Last diving season I finally figured out the frenzel but have not needed it this season as we did not push ourselves very hard. Can anyone tell me what it is that I am doing wrong??