I have read many times that you have slow connection, I don't know if you know this trick but sharing here what i do follows and can be helpful.
-Copy your ROm file to your device
-Add dropbox account to device and upload from device with wifi (you can do with PC but mobile is convinient and you can do it interrupt anytime and also can use any wifi point if you have access

) on your
public folder of dropbox OR if you forget to upload to public folder - read below
-Don't worry about break you can upload in piece and it will resume from last.
-Once it finish open you dropbox from web and look your file, if it is not in public folder just Rt click and make copy/move to public folder (it take few sec)
-Now from public folder Rt click on file and select - Share public link - once you get public link just copy iy
-Now IMPORTANT don't share this link in public if download cross >2GB your account public sharing will get banned.
-Open pcloud (free you can make if not there)
-Select upload - select remote upload - paste your public link and within 2 min it will be copied to pcloud server
Share ploud link and ask anyone to make mirror
Enjoy !