Practicing mindfulness when I'm feeling doom & gloom is the most helpful technique. For instance, I think about right NOW. Enjoy this very moment. What can I do to feel okay? Sometimes, coloring helps. Or, listening to the opposite mood music. Imagining myself in the mountains or at the beach, and putting all effort into imagining as much as possible: how the air feels, sunshine; hearing water trickling through the nearby brook or waves crashing down on the sand; hearing birds chattering, pine needles crunching as I walk and pinecones falling down every minute or so; sights; how things feel as I touch them (cold water, sand or dirt, rocks or shells; etc.

It only takes about 5 minutes or so, and my stress level drops considerably in that time. Then, I just keep doing it over and over as long as I need to escape dark impulses. It really does help me a lot.

Just keep trying. Things will get better, and then you can take up current stressors from a clear state of mind. I'd also advise you to talk with a T about the issues hounding you: past, present, and future. let them help you work through things. Best wishes sent your way.