HELP! Can you die in your sleep from sleep apnea?

My boyfriend said I snore and I have chronic sinusitis. I went to my ENT and he said I may have obstructive sleep apnea because my one nostril is blocked, I have large tonsil, a narrow soft palette, & I'm overweight. My sleep study is scheduled for next week. In the meantime I'm scared I may die in my sleep from apnea. I just had a physical and I'm in perfect health otherwise. I'm so scared.