I agree with you, more than your coach. Just analyzing a GM game, even with a computer, is not helpful just by itself if you have no idea what is going on.
For example, just earlier today, I answered a question here, where the person gave a computer line that made no sense as far as the plans for the position were concerned, so the computer was really no help at all there.
I think what you need are grandmaster games that are WELL-ANNOTATED, to tell you what is going on in them IN WORDS, not just variations, although concrete lines are clearly important too. Another thing that happens in modern chess is that games between IMs/GMs have become so advanced that the battles between each side's plans have become too complex for learning early in a chess "career" because the plans are so effectively thwarted by the opponent it is not always clear what each side was aiming for.
What is much better are the games of old masters like Capablanca and Alekhine because their opponents, while not slouches, were not on their levels; so you can see plans more clearly executed from beginning to end as the plans were often not met with the type of resistance that you would see today at the top levels.
I would get collections of their games, written by them, and play through those games. I have also written here extensively about opening pawn structures, and as you read any game trying to understand it, you need to have some understanding of what you are striving for in any given opening.
Another book that is extremely good for learning is "Learn from the Legends: Chess Champions at Their Best" by GM Mikhail Marin.
Learning to calculate is really a different skill, but one that is reliant upon how well you understand chess (see above), in general, and what you are aiming for (that is, what is the plan).
Calculation prowess can be gained by combining two practice activities: Reading pure tactics books, and reading books that have non-tactical positions for you to practice calculating the best move. Also, try practice reading annotated games without a board, including the annotations, to work on vision in your head.
Tactics books are self-evident as there are a million of them out there. Some excellent books that will give you positions to calculate (mostly) non-tactical positions include:
"Positional Chess Handbook: 495 Instructive Positions from Grandmaster Games" by trainer FM Israel Gelfer. I cannot even begin to tell you how much I love this book. It is incredible. (Do not get the Kindle version as there are way too many mistakes)
"The Best Move" by GMs Hort and Jansa.
"Test Your Chess Skills: Practical Decisions in Critical Moments" by GMs Sarhan Guliev and Logman Guliev
These will help you improve your pure calculation.