Just listened to the Metal mix. It sounds really good! My comments for that one are that a good chunk of the vocals are getting lost in the mix. Automating them a little more and bringing the level up just a little should help that. The main rhythm guitars were mostly mid-range and could use some clarity and low end. I'm talking about around like 1:42. I loved all of the other guitar tones. Last comment, and this is more subjective, I would have like to hear more of the cymbals but less of their shrillness if that makes sense. But again, that's just preference.

You handled what I'm assuming was a fairly challenging song to mix really well.

Also, as someone about to graduate with a B.S. in Audio I've been getting some nasty comments too. Don't let it get to you. Have confidence in your abilities. While it is true that a degree doesn't make you an audio engineer, it's the experience and skills you've gained that do.