How do I file?!

So last tax year 2018 I filed with my then girlfriend.  Our tax preparer at H&R block suggested we file as married so we did.  Unknowingly to us that meant we were now common law married.  I am now trying to file this year and we have seperated.  We have two children 8 months and 5 years old.  Do to lack of funds we haven't gone to a court but have made agreements on our own.  She has been unable to move out of the house I own because she has no family living close and she has no job do to a disability which she is not recieving disability for.  

 

So..

·we are separated

·we have two children

·she still lives with me to care for children while I am working

 

How do I file?  I don't want to be held responsible for her student loans, and I dont want to wait the 8-14 weeks for my return with the injured spouse and she refuses to file separately.