Adam, May 19, 2020, 2:39:23 PM PDT:
Due to Web limitations, you can not upload folders that are larger than 50 GBs, and or, contain more than 10,000 files on www.dropbox.com.
The Dropbox desktop application can handle files and folders of any size or number and is the preferred method of uploading files.You can read more and find a link to download the application here:https://dropbox.com/help/65What you essentially want to do, is drag and drop your data over to the Dropbox folder created when the desktop app is installed.
For more information on how to add files using the Dropbox desktop application, you can visit the following link:https://www.dropbox.com/help/4455
Normally Dropbox doesn't use all of your bandwidth. However, you can change that by manually to throttle the sync process by setting the upload/download speed:
1) Click the Dropbox icon in the system tray, or menu bar, by the clock on your computer's desktop
2) Click on your profile picture or initials to the right of the search bar and select "Preferences" from the menu
3) Click the "Network/Bandwidth" tab
4) Click Change Settings next to Bandwidth
5) Set the Upload and Download to a specific kB/s limit if you know your connection speed or simply Don't Limit to allow Dropbox to use as much bandwidth as possible
NOTE: Setting your Upload to Don't Limit or a higher number than your connection is capable of will likely cause all other Internet activity on your network to slow significantly.
I hope this information helps. If you have any further questions or issues, don't hesitate to come back to me.
Kind regards,Adam