I am from Brazil and i wanna get a better connection to Elder Scrolls Online. Im using 240 mpbs download speed and 20 mbps upload should i use fast internet conection ON ?Thanks.
It doesn’t be a matter and as you might know the network bandwidth doesn’t help to play the game at the international game server. 
However what ping do you get with or without Mudfish?
With mudfish inside game im getting 230+Without it im getting 220+
Dunno why is it getting worse
Did you try to change a mudfish node based on FAQ - Nodes section for your game item? If you’re using the advanced mode, please start with the basic mode.