Can you go to this website and tell what speed it gives you?
https://fast.com/I have 150mb/s fiber connection and that site gives me 150mb/s result. My actual download speed is about 15mb/s.
It says 19mbits.
Damn, so you probably have a 20mb internet connection and can download BG3 like 1,9mb/s. Man, it's gonna take a while for you...