Your current settings are not going to work at all. You have effectively set your bitrate to a value that your network can't possibly work with, as you barely have 2Mbps upstream. You're not going to be able to stream 1080p, nor are you going to be able to stream 720p with decent quality. You mention that the estimator isn't very useful for you, but the settings it comes up with will be much better than what you're using now. Your current settings are all over the place.
I agree with Dodgepong. To add to his points:
- Lower your audio bitrate to 128 or 96kbps. You barely have sufficient upload speed for livestreaming. Not only is the higher bitrate unnecessary, but it basically wastes kilobits that are better used for the video parts.
- Get rid of that CRF=18 custom setting. This setting skyrockets the bitrate of your video. This is completely unnecessary for livestreaming purposes.
- Treat the 1500kbps as an absolute maximum bitrate for your video. As stated before, you barely have any upload speed (for livestreaming). The total bitrate you'll stream at will be the video bitrate + the audio bitrate. If you're going to be playing online games you want to make sure that you have some headspace so you can still reliably play the game without overloading your internet connection.
- Set your scene buffering time to 700ms.
- If you keep getting dropped or late frames, consider dropping the webcam.
- Use wired internet instead of wireless. For obvious reasons.
- Lastly, remember to not use monitor capture to capture a game. Instead use Window capture or Game capture. Monitor capture is the least efficient capturing method.