You have a decent voice and make pretty good content, however, your microphone isn't great quality, is quite fuzzy and picks up heavily on background noise, 1080p is admirable but your system is clearly having trouble with it, the framerate in your videos isn't so smooth, it'd be much better to record smoother footage in 720p than choppy 1080p, there are black bars on the top and bottom of your video, this means your resolution is wider than 1920x1080, not too hard to fix, if you have optifine installed i'd recommend going into the graphics options, and under the "other" menu you'll find fullscreen resolution, switch that to 1280x720 and that will have a great effect on both your performance while recording and it will eliminate those ugly black bars.
back to the audio, if you're serious about keeping this up, then you must address this, high quality audio is one of the most important things, a cheap tie clip microphone is great, personally i got myself a headset with a great mic, the Logitech G35, ultimately a decent compressor microphone is what you want, but those are considerably more expensive, but seriously, fuzzy audio is really bad and will have a huge impact on the success of your channel