For about 2 years ive been struggling with my lags ingame. But now its ridiculous. I havent been able to practice normally at all for the past 2 weeks

I dont understand how, for example, my friend can download torrents and still play just fine without any lag but nobody in my house can even watch a youtube video without my ping going to 150
Its not wireless either.

What can I do to avoid everybodys internet usage fucking my lagometer completely?