Check out time?...

I awoke this morning with tremendous anxiety of the future; my marriage has been giving a 1yr timeline before me and my wife make the transition to separation and then divorce.  I feel very angry, bitter, frustrated, on top of being depressed, and have turned this internally on myself and her.  I told her that I'm giving up now - why try to rehab myself if I have no future to look forward to?  If I'm this miserable now, being alone & seeing my son only on weekends will make me feel better??!!  I now feel really trapped and that I only have one alternative.  I already have a gun and am really thinking about turning it only on myself and getting this over with...