I feel you, I really do. I have the same gap between doing exercises and actually drawing something I like in the end, the feeling of achievement instead of feeling like you're going around in circles.. Seeing an actual, tangible result. And it doesn't help that what I'm hungry for is transforming what it's in my head into art instead of empty practices (which I'm guessing is the same with you)
Even though I faced the same issue (that's why I went back to term 1 to do things differently) so maybe I shouldn't be giving any advice lol but I can tell you what my plan is going forward and maybe that would help.
You can start focusing on 1 subject (for example face anatomy) and use the exercises to draw a character you really love, instead of the generic face we practice with Marc in the lessons. I know it's frustrating when you don't achieve the result you want to achieve, but try to get into the mentality of obsessing over a certain mission (ie drawing the face of your favorite character) to push you forward in trying until you're reasonably satisfied with the result. Remember, it doesn't have to be perfect.. it just needs to meet the requirement of the lesson (how to draw the face structure, the nose, the eyes, etc) and try to do that with every subject (for example a favorite shot from a movie, animated or otherwise, to learn perspective) Think of them as mini projects. Also, I would focus only on line art as a start. Whenever I get into coloring and shading I get lost. Try to get the general outline and when you're satisfied with what you have, move to the next element.
I wouldn't be sure if this will work but the idea is to not overwhelm yourself with so many elements of the art to the point of feeling lost of what to focus on, and to also enjoy drawing images/characters/environments/movie frames that you hold dear to your heart. You will enjoy the process more that way, I think.
Again this is all conjecture, I didn't even practice what I'm preaching yet 
I'm taking it slow, and maybe you should too! Take your time with each lesson, and go back to one if you feel you didn't grasp the information well. And if you feel burned out, take a break. you'll be more clear-headed about how to tackle any issue you face after a break.
Sorry for the text dump 
I really hope this can help. Let us know if you're stuck with something specific.. I'm sure everyone here will try to help and give constructive feedback. Don't worry too much, it's a phase.. it'll pass once you figure it out, and you will figure it out 
