Writer crashing repeatedly.

Dear designers/programmers/creators,

I am trying to use LibreWriter to transcribe an old diary for Family History purposes. I need to have landscape document with three columns and have this. I have entered text and saved it after every entry but after half a page is written suddenly a letter changes size from 12pt to minute but there is no change on the menu ribbon. Then, when I tried to delete it the whole document went blank and an error message said that Writer had crashed and to try to recover what I had written. I am using a new hp laptop and Libre Office is the only program installed. I save to a folder and tried to set up a parallel save to a USB as backup, but this does not seem to work.

I like Libre but some things are buried deep in the drop-down menus rather than easy to find and set up. Your manual is very complex and helpful but terminology is sometimes oblique.

I started this project thinking that Libre Office would satisfy all my requirements. Tried using LibreCalc to transcribe the diary. Completed 2/3 of a year then discovered that, despite saving after each entry and saving before closing that there were large gaps in the re-opened document.

I have studied the manual for both Writer and Calc and decided to try Writer, setting up a landscape format with 3 columns and it seemed to work well but then it crashed.

What am I doing wrong?

R M Dearden