I'm going to do my best to describe how I do continental knitting...
I hold my yarn a bit differently then they do in the video and I have found that it is easier for me to control tension.
I hold the yarn in my left hand, put the yarn between my pinky and ring finger, over the back of my hand and then wrap it around my index(first) finger twice. I find that my first finger can pull a bit tighter when I start to loosen up or I can put my finger closer to the needle and give a bit more slack when I get a bit tighter. Now I do have to re-thread through my hands from time to time to get back to correct tension. I also use my index finger to wrap the yarn around the right hand needle, instead of using the needle point to wrap around (not sure if that makes sense)
I hope that helps... if not let me know and I'll try to take a picture of how I do it and post.
watch your CO tail yarn on the first row - it looks like from the pictures, it got picked up and knit into your first row or CO row. I saw on another post that someone uses the plastic tabs that hold the plastic bag on your breadloaf closed and wraps the CO tail around that to keep from knitting it into the work. I usually just watch and if I do grab it, stop and gently pull it out, and give a slight tug to straighten it out.
Keep practicing... it may be worth it to knit a few swatches using continential till you get the hang of it... My grandmother taught me and I spent a summer CO, knitting a swatch, taking it out and starting it all over again. I didn't appreciate it then, but I do now.