Don't try to be happy - stop making yourself miserable instead

Stop blaming, punishing, shaming, regretting, sabotaging, deceiving, hurting. At least in the first instance. See how life becomes more manageable.

Happiness is there always underneath all that other crap. If you want to achieve happiness, stop blocking what is naturally available to you by choosing to live miserably.

If action is required, do that. If no action can be taken, accept that, and just stop.