When were you admitted as F-1?  Was this your first entry to the USA ?  Which country are you from ?  Are you still a student (F-1 valid ) and is this an extension ?

I was admitted 5 years ago. I have filed for taxes until last year. So I have to file for the last year and this year. I am from India and this is mot an extension. And I still have a valid student visa and i-20. I am also currently taking classes..

Once you have passed the  five calendar year from the year of original admission  e.g if you were admitted in in 2013 then 2018 is the first year you would start counting days present and thus it is possible  that 2018 you would be a resident alien for the year. So in such a case though 2017 ( if you had  US sourced income ) you would file form 1040-NR and 2018 would be the first year you would need to file  form 1040 ( supported by TurboTax).
So when did you enter the country? Are you on OPT?  What is the source of your income?  Did you file form 1040 or 1040-NR in 2017 ?

Namaste ji