No one can tell you on a web site what is the proper response to make in your case. You would be much better served to file a Motion for Enlargement of Time - today, by hand, and get a clerk-stamped receipt - and the find an experienced foreclosure defense attorney to review your situation with you in order to decide what should be done next. Do not let the fact that a response is due tomorrow crowd you into making a serious mistake.
You definitely need to consult with an attorney. Foreclosure defense is very technical. Any response to a Complaint must be tailored to the allegations in your specific complaint.