Seconded. i5s are great for gaming rigs, but they run out of steam much past 720p@30fps when gaming and livestreaming. You're going to need to downscale. Also, I'd recommend dropping your audio rate to either 96 or 128kbps. 160 for AAC is generally overkill. Likewise, streaming at 3500kbps is definitely NOT advised unless you're a Twitch partner. Most of your viewers will go into permanent buffering-hell.
Sweet spot for non-partners is 2000kbps, 720p, 30fps.