Hi Foggy's friend -
Darkness feeds on fear and saddness - so don't feed it.
One way to keep the darkness at bay is to shield yourself. Envision a bright white bubble around you (if you want a more indepth shielding exercise - you can visit my blog - under podcasts -or search it on the web).
Erin has wonderful information on her blog - here is one entry
Erin's blog
Wish you the best!