Help me please!

PLEASE HELP! I am somewhat of a compulsive worrier, I tend to worry a lot about things happening to my notes, I've been using this software for about a year now because half my google docs were mysteriously deleted.

Onenote has proved well for me since then, I've started writing my stories on there and I had one very long page (which will play part later) and I wrote, I wrote a lot and I have over 400 notes.

I've began to worry about things happing to my notes, I mostly use the app for context.

My onenotes would be lost or deleted

My notes would be hacked

I would forget my passwords

I would worry almost every day about that before I went to talk with someone about it, it was agony, complete agony and still is. A few days ago I sighed in and out of onenote and that super years long of work note was gone.

I stayed on six or five hours with customer support, which didn't help (And now I discovered just last night that I'm able to open it, it just freezes when I try to edit it and won't load the whole page) Now I fear that I've done:

Irreversible damage

That I'm still going to lose my notes

I've begun to lose my faith in the software. I mostly use the app and sometimes the website, but will the long note crash all my others?

Thank you.