Here is the full list of all 10 Sickness achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Spend eternity with Sara
Give up everything to stop history from repeating itself
Cohabitate with Misa
See this season's biggest blockbuster
When things get messy, neglect your duties
Turn the tables while being seduced
Kill Mr Roth while he's indisposed
Attend counseling
Turn down the opportunity of a lifetime
Fail your first paid kill