Help! backup warning aboven my site.. can’t edit anything

Help! I did nothing to my site, and overnight this happened:

https://www.beautygloss.nl/

See, aboven there is this:

Warning: fopen(/home/beautygloss.nl/www/wp-content/backup/.htaccess) [function.fopen]: failed to open stream: Read-only file system in /home/beautygloss.nl/www/wp-content/plugins/backupwordpress/functions.php on line 377
Cannot open file (/home/beautygloss.nl/www/wp-content/backup/.htaccess)
Warning: fwrite(): supplied argument is not a valid stream resource in /home/beautygloss.nl/www/wp-content/plugins/backupwordpress/functions.php on line 381
Cannot write to file (/home/beautygloss.nl/www/wp-content/backup/.htaccess)
Warning: fclose(): supplied argument is not a valid stream resource in /home/beautygloss.nl/www/wp-content/plugins/backupwordpress/functions.php on line 385

I can’t edit anything or leave anything at the comments etc. In an hour a new post will be up (automatic) and I hope that won’t mess it up.. I made a back up this weekend luckily, but I don’t understand why this is happening.

Should I go into my ftp and just delete the whole backup plugin? will that help?