baby anxiety

As of Novemeber 11 i started attending school 53+ hours a week and my daughter was at a sitter all the time.  i was only going 20 hours a week.  now that i have graduated she has become increasingly nervous that i'm leaving.  i can't even go into another room without her crying.  is this just seperation anxiety or should i be consulting a doctor?  i also can't get anything done during the day because she's so clingy.  my LO is 18 months.