One of the things I do to try and help myself deal with bad situations is just concentrate on the current moment; Not 5 minutes ago when such and such was bothering me (reminding myself that such and such is not currently near/active anymore--that's the hardest part); Not 5 minutes from now when (I imagine) the horrors awaiting me that I have to handle.
I try to concentrate on the sounds around me. What can I hear? I rub my finger tips on something near me. What does its texture feel like? I look around. What do I see? How far away is it? Without looking, what is behind me? Glancing back, was I right? I use as many of my senses as I can to ground myself in what is happening NOW, this nanosecond. Not the instant before or after but right now.
I know I have to actively do that otherwise I tend to obsess on things. Relive conversations and how they could have been handled differently, or (usually wrongly) imagining all the bad things that will be happening in the immediate or far future, it doesn't matter. 5 seconds from now and 5 years from now are still NOT *now*.