Hi Lob15,
First i see you used FileZilla software for FTP Upload and this is good soft, and you are single that report this problem on ftp uploads.
Now i have few question for you.
First, do you use VPN ? (In many cases they will reset the bandwidth for the country you use it and this will be a cause that you lose the connection with gounlimited.)
Second do you use RDP ? (Some providers or more precisely use shared bandwidth, if a user on the same server with you is much more active than you, you automatically lose speed and even the connection between RDP and GOUNLIMITED.)
Do you tryed to active your FILEZILLA auto connect ? (Edit -> Settings -> Connection -> Retry Settings)