there is nothing wrong with reading off a sheet, so long as it remains on the table, and not held up in front of your face.
however, this is what worked for me some years ago...........
break it up into segments, paragraphs or 'chapers' if you will.
memorise each one before you move onto the next one.
when you come close to the day, think of a title for each piece, write down on a sheet only the title (rather like a bullet-point list).
have the sheet on the table on the day, and when you briefly glance at a title - it will, hopefully, make you remember the paragraph to which that title belonged.