Hi Nicholas!
I think you do a great job keeping the bar close at the start of the rep. Nothing to really fix there. It is most definitely locking out behind your shoulders at the top though. Try to visualize throwing the bar up directly over your shoulder and covering your ears with your biceps at the top. You'll waste a lot less energy and the lockout should feel easier.
Next time, can you post a video from a front 45 degree angle? This will let us see other important things like your grip.