miserabilism
Concise Oxford English Dictionary © 2008 Oxford University Press:
miserabilism /ˈmɪz(ə)rəbɪlɪz(ə)m/
▶noun gloomy pessimism or negativity.
– derivatives
miserabilist noun & adjective.
miserabilist noun & adjective.
'miserabilism' also found in these Oxford entries:

