My Brain Wants to Torture Me

I’m currently going through a very difficult time in my life (probably the worst I’ve ever been through).  I notice that my brain is very good at imagining the future in the worst way. It is insisting on horrible details of what is happening these days, or thinking again and again and again about the very sad stuff going on.  It is similar to a very cruel persecutor knowing exactly how to make me want to die right now.  Sometimes I think, “Come on, I can’t be like this all the time.  I have to stop the pain for a time out once in a while.  I need to take care of the kids and work.  I can’t cry and panic attack all of the time.  I need to manage my brain like I learn at Scholars.” , but my brain seems to be stronger and I find it very hard to make it “obey” me and let go the horrible thoughts.
Any ideas to help?