I had some time to spare, so I saw it. Yea. Since you've been brave enough to put yourself on the line like this, I'll be honest.
What holding your breath has got to do with anything is beyond me. From my position it sounds like someone saying "I can lift a wheel so I should be able to drive a car". True, being in good shape is a huge bonus, and a bit of thorough exercise before vocal practice is in my experience great.
To have been practicing vocals on your own for six-nine months might take you to the starting line, unless you're one of nature's singers, there are quite a few around. I've been taking private lessons with an opera singer, trained with various people, partaken in a bunch of shows with singing and singing/dancing, and sung in a choir, for well over a year; not counting the years before that when I practiced on my own. Three weeks ago my teacher told me that I got everything right and could start getting down to serious business. And though I lack natural talent, it's far from a unique story, learning to be a truly good vocalist is in no way easier than becoming a great guitarist. It's a matter of both years and every day, pretty much.
You don't have a free tone, judging from this. You're closing your throat to it, send the force straight up into your head and then kill it off by clenching your jaws. This is what most of us do, evolution hasn't been favoring good singing capabilities for long enough.
It's a bit hard to see, but I don't notice much bellow action below your rib cage, and where you're pointing is on another continent compared to what I'm talking about. As the lawyer in the vocal class said "Does Astrid mean all the way down by the clock works?" and so Astrid almost did.
Your shoulders tense. Not as much as mine did a year ago, but they do. Stop it. For all practical purposes you're strangling yourself.
I said you're closing your throat. I can see this on your Adam's apple - it's higher up than it should for your throat to be relaxed and working smoothly. I'm not entirely sure what it is you do in growls and screams - I can check it up for you - but when I say "closed" it's a matter of something merely harmful and only that. It's like someone told you to run a hundred meter as fast as you can and then hang a rope with two large bags of cement around your neck. Your vocal cords and their supporting muscles are weak and fragile and will remain so until they rot, at which they will be even more fragile. When people say that they got stronger vocal cords, they have intuivetly found a better way of using them.
I said you're sending it straight up into your head. Consider a head. There are cavities, but not a the top. Apart from the obvious ones, the interesting ones are situated in something called le masque, a splendid opportunity for me to play wiseguy, since it means the mask and is simply found where a mask covers your face; around the eyes and nose. Get the force in here and you're basically throwing into an echo canyon. Imagine that you're aiming the air strem at your cheek bones was my teacher's advice, though for me she had to go a bit further and say to aim at my forhead before I got it into my head, pun intended, wabba-da-dam. Now, you might think "but that's head voice, that's something opera singers use for high notes", no, it's useable for whatever damn sound you wish to make.
Clenching your jaws I said too. That doesn't mean you're grinding your teeth, but to allow for the full potential of your voice you need to jawn. Further on, you can skip the wide open mouth part if you're not singing something that requires that particual sound - such as Nessum Dorma or Opeth's Ghost Reveiere - but not really until you learn to relax. There's a simple way to test yourself for this. Jawn, as if you were really tired and feel with a finger along the back of your jaw below your ear. Flex from closed to jawn a few times and feel around. When you're gaping wide, you'll feel like a small hole opening - this is what you want at all times when doing vocals. Let your jaw form the words of your song instead of giving you a head ache!
Why am I going on about this stuff? Because it's some of the things, some of the most important things, that have allowed me to stand before an audience of sixty people, with music coming from loud speakers but no mic, leading people in communal singing and helping the ones at the back finding the tone.
I've only outlined what is available to use for a singer that I have some hunch of how to use; there is more. And one thing I can tell you for certain - after watching - is that it's worth it for you to put in the effort. This will sound like a contradiction, and would take even more ranting to explain, but you got a fairly good positioning of the tone itself, and have a good tenor voice that is well worth developing wether you wish to go for troubadour at parties, extreme metal or both.
But I need to go now, and anyhow have been enough of a know-it-all to last for some time!
Listening to Slipknot and cutting yourself is ridiculous
Listening to Cannibal Corpse and cutting trees with a chainsaw, now that's metal
"He preferred the hard truth over his dearest illusion. That, is the heart of science."
- Carl Sagan
"Imagination is more important than intelligence" - Einstein