I know the uber stressed headspace, it was/ is my playground. Rather than borrowing trouble from the future, or picking up past troubles, live in the present. If your head starts yammering away that omigod, omigod, omigod [stressful thing], put away that stressful thing, temporarily. If you can't do that for an hour, do it for a minute, even a breath. Then the next minute or breath ,and on. When you have found your calm, allow yourself to enjoy it. Yes, you'll hafta pick the stressful thing back up, but you can pick them back up one at a time, examine them and what is causng the stress/ anxiety about it. Figure out a solution, even a temporary or possible solution, and implement it. Then put the stressor back down. If it has a path, it doesn't need to be on your mind.