Could also try your GP or DAME. They will in most cases be able to refer you to someone local for immediate help, and would probably have the contacts to find someone aviation specific if the avenues above don't pan out.
In most cases people just need a few sessions to 'talk it out' and get things off their chest to someone outside the incident. A good program for PTSD (if diagnosed) will always let the patient opt back in at a later date should any other issues arise (for example, a later beareavement or relationship problem may in some cases trigger off the same anxiety as the initial incident)
You could also try googling the Centre for Clinical Interventions, they have some online workbooks designed to be used in conjunction with counselling if anxiety is an ongoing issue.
All the best for your friend.