Managing stress is stressful itself. One way to cope up with your kind of stress, whatever it is, is to find out what made that particular situation to be stressful. Sometimes a situation is not stressful itself, but you yourself will make it more difficult by doing unnecessary things to make it more complicated and that's what makes it so stressful that you yourself cannot handle anymore. Handling stress is a matter of mind perspective. It's really up to you how to manage it. Be calm, relax and focused. In these way, you can think more, than being historical and panicking.