I recall my last passphrase but I was copying it from notepad .txt file. I opened up the txt file but guess what? Doesn't open! I cannot access this .txt file anymore.
What error are you getting when you try to open the .txt file? Is it a "file not found" error or something else? 
It seems odd that you cannot open a simple text file... they aren't stored in a "special" format or anything like that, so should be able to be opened by any text editor.