Some ideas:
Stay awake during the day and sleep at night - take meds to sleep if you need to, a good nights sleep is really important.
Get out of the bedroom/ house, have a shower and get dressed, exercise if you can
Journal to get those destructive thoughts out of your head
Try to find good things in the world around you and focus on them.
Write lists and take baby steps of what needs to be done - one thing at a time.