Trying to develop the speed to keep up with full speed recording seems almost impossible. Is it really necessary to play it that fast?
It's not impossible, you just need to work on it more. This is of course the Beginning Blues Guitar Unleashed course, so EVERYTHING is verry likely hard ( it is wasn't then you wouldn't need to take this course)
Be sure to start with the slow track and if that's still too fast use software like RiffmasterPro, Audacity or any of dozens of free apps that can slow it down for you. If you are playing along with the video, remember that you can use the little gear icon to slow the video down too (Either 75% or 50% speed).
Count it as you play. Slow it down enough so that you are playing the notes in the right place.
Occasionally take the speed up by 20% to remind yourself that playing it slowly is not the goal.
You should find that after you have it memorized and played accurately at slow speed you will be able to bump the speed up 5%-10% Every day until you are at or beyond full speed (it's a good idea to play it at 105%-110% for a little while because you want to know that you can play it and still have some "in the tank".