I ended up exporting the flows as json, and of all things I used windows notepad and replaced the words. Saved the file.
Deleted my running flows in Node-Red (except for 1, which I renamed delete), imported the new file, deleted the "delete" flow, and restarted the flows (no error messaged) and then I tested it and it works perfectly!
This can be considered closed and solved, thanks to you all!
A couple of ways i back up: just manually export and save the json files for all flows when i do major changes to it AND, as you guessed, home assistant does full system backups, every few days, locally and on the cloud .
I should confirm if HA actually does save my flows...it should .