I'm sorry today is as stressful for you as it obviously is per your posts.
DIII is holding up reasonably well given the ugliness of the markets today. It is obviously an ugly day. You need to follow the plan you had when you put your money into this stock. If you didn't have a plan, you need to get one. More than anything you need to determine your acceptable risk level. ( I think this has already been posted on this board. )