My audio can be heard from friends and others on mic, even when muted.
Ive tried most things to fix it, but none worked, so i was thinking of buying one of those 3.5mm usb jack thing, would that be the way to go?
"youtube videos, music, notifications etc can be heard by my friends despite me muting my mic. this can't be audio escaping my headset into the mic"
That is really odd. Because if you have muted the sounds, and you can't hear it in the headset or speakers, then no one else should be able to hear it. Now if you can hear it, others can hear it.
Now if you are muting the mic and not the sound, that is different. Then it is possible that you are using the computers mic and not a headset one. Which happens often if connecting through a 3.5mm port that is either a combo one or just a headset on.
In the case of the first thing, an adapter won't help. If, however, the problem is the second listed, then a 3.5mm to USB adapter should help.