-s3-upload-concurrency should be --s3-upload-concurrency
many uses have copied larger data sets than you.
i have done a couple of 30+TB transfers.
rclone limits are dependent on the flags you use and the cpu and ram.
perhaps your computer cannot handle your settings or can handle much more.
you can get an estimate by reading this
https://rclone.org/s3/#multipart-uploads
" Multipart uploads will use --transfers * --s3-upload-concurrency * --s3-chunk-size extra memory. Single part uploads to not use extra memory."