Yeah, unless you're a Partner, 1080p isn't going to fly. Even at 30fps, 3500kbps isn't enough, and will cause your viewers to go into buffering hell too. For 1080@60 you'd want closer to 6000kbps, which will render your stream unwatchable to probably 90%+ of Twitch viewers, and could get your account banned as a DDoS attack/abuse.
The 'golden point' for non-partnered streamers is 720p@30fps, 2000kbps, x264 Veryfast (or lower) with 96 or 128kbps AAC audio.
Take heart though, you can probably drop the preset a lot further (likely to Slower) which will use MUCH better compression (and a lot more CPU), making your stream look significantly better at the same bitrate. Which is super-important when non-partnered, to work within the realistic 2000kbps maximum. Most people can watch without buffering at that rate; even going to 2500 will cause a significant increase in buffering, and people leaving without saying a word, for a channel they can watch smoothly.