I need a rubber stamp to always say "ride more forward".
You tend to look down and I do also but if you do look down be a little less obvious.
Here is what I saw. Very inconsistant riding, You don't seem to finish anything even with the edits. There doesn't seem to be any goal or reason why you ask for a canter, for you go a couple of strides then walk or trot. It is almost like it simply becomes an idea at the moment.
What your horse and you need to do is stay at any one gait until the horse is calmer, more relaxed and willing. I see that when he just starts to drop his head, you don't seem to be aware of it and rush off to do something else. This is probably the reason he hollows his back and rushes because he has no idea what is going to happen next.
What I am trying to say isn't easy to put in words but lets say that if you had a very professional trainer you would be trotting for 5-10 minutes SOLID with turns, circles changes of direction and multiple exercises thrown in before you would be allowed to have a brief walk. I would not expect to get a break and walk just to change direction. The canter is the same, needs to be more continous which will lead up to a jump that will not be rushed.
This is not really a critism of you for I find many young riders often don't have mindset to stay at one thing until a goal is reached. It needs to be trained into the rider as much as it needs to be trained into the horse.
If you can train yourself to be more patient with a sort of one tracked mindset you will be surprised the difference it will make not only in the way the horse goes but in your expectations.