This depression hit me like a bomb! any ideas to alleviate it?

for the past two years i have been a caregiver for my mother with dementia..it is difficult. i would rather work and move on!..mom also has a bad heart and is given 12-18 months,,everything was fair in-till a friend of 30 years dropped dead.he was on vacation in venezuela visiting relatives..he started to cough uncontrollably..and collapsed..that was it!..i now worry of my strain of caring for my mother and truthfully...now have depression and not feeling the greatest..my health insurance ended when i stopped work..there are clinics but you have to apply and i was refused...great obama health care for all..i want to snap out of this funk i am in and breathe some fresh air..please advise.