Just some suggestions through the tough times:
- Talk to friends and family who understand
- See if there are ways that the work done can be absorbed into another company
- Drop a note to mentors/ advisors when you are professionally ready
- Do some small projects for companies in your network who can pay on time, and hopefully also let you slowly ease into a different team and environment
- Cut down on expenses
- Plan your project portfolio and resume
- Try to do at least some light exercise regularly (e.g. 3 times weekly)
- Try to see how you close the loose ends (tough, but take as much time as you need and take into account your mental state)
- Don't force yourself to go all out socially
- Write down thoughts about why you think the startup failed, organize it later when you can look at it calmly
- Don't try to over-analyse the situation
- May want to explore meditation
- May want to explore religion as a way of thinking about life's meaning and putting things in perspective