Youtube doesnt have explicit stuff i think,like no naked people, but they have a lot of suggestive stuff. I remember the first time i searched pakistani i got all of these pakistani mujra girl videos lol...anyway yup i did click a few, it was mostly like "what the hell, why is she jumping so much" but maybe someone could've thought i am doing something bad.
a similar situation happened to me of finding someone else's computer stuff...my heart was beating so fast afterwards, idk why i felt really scared and shocked and disgusted all at once...but my sister said not to freak out and she said all guys do this. i was kinda sad to hear that, i guess i was dumb and thought "shareef log" dont do this. but she said, it's their curiosity and stuff. i was so so upset. i felt betrayed and grossed out..like i wanted to wear a tent cuz i didnt want anyone to view me like that.
Well I think limiting the opportunity is good. In our home, we have set all electronic stuff in our common areas. It's not for prevention of perving specifically, but my mom doesnt like k hum saray apne kamron mein gussay rahein. issi bahane you can have the computer moved also. i bet your brother is already sharminda enough and is probably avoiding you so whatever suggestion you make will be approved.
Btw islamic books are not always the best...omg i remember when i was 14 i read a book called "bahishti zewar" and it gave something about ghusl after being with an ANIMAL..omg i felt so sick and dizzy afterwards...it gave me images that i never even imagined!! so be careful! it's an effed up world these days!