for a quick fix, do a speedtest.net
keep your kbps around 500kbps less than your upload
do not exceed 2,500kbps unless you're partner.
use 30fps
since the site is saying you have a weak cpu, keep your resolution at 960x540
put your preset on veryfast or super fast
play your game and keep an eye on the cpu usage, if it goes above 85% change the preset to something quicker.
the quicker the preset the less cpu usage. this will cause the video to have less clarity but at least you'll be able to stream.
if continue to have issues, i can help you out using teamviewer.
be warned anything you can do on your computer i can do with that application. so i wouldnt advise letting just anyone mess around with it.