how do I return my document settings back to normal as they have all doubeled in size I also have a line through all my text whenever I open a document

On opening documents all script come with a line through the middle of it, the documents have doubeled in size even though it still reads Areal point 12, I cannot seem to return things back to normal, can you help please

The title is too long, and there are no sentence breaks. Please put more effort into asking a good question.

This is probably two different issues, answered at libreoffice editing, how to get document with the strike throughs deleted? and I don't know how to increase the size of the writer document.