@Katie1996 , agreeing with the points made by my colleague @Opus 17 , we need some more info about your situation -- that will make the answers here more focused to your case.
(a) Are you a US person ( citizen/GreenCard / Resident for Tax Purposes )? From your post it appears that you were/is a Resident for Tax Purposes --true ?
(b) If you are a GreenCard or Resident for Tax purposes , how long were you in the US -- this is because , long-term US persons need exit/ sailing permit.
(c) Which country are you in now ? From your post it sounds like you are not a citizen of that country.
(d) Residency is determined for each year based on SPT ( if not GreenCard ).
Note NRAs with US sourced income generally are not able to claim standard deduction and you essentially file as single ( single or otherwise ).
Please answer the questions above --yes ?
