This is an interesting question. You were basing your play on some useful truisms without considering if they really applied. "I need to free my position with f5." "I should make Pawn captures toward the center". "He will not want to give up his good Bishop", "I should not waste tempi" All true, individually, but almost nothing is true every time, which is why chess rewards creativity. Before basing your play on general principles, it is wise to ask why do those principles usually apply? and do they apply in this position? GMs giving simuls rely on general principles because they must, but they do not do so thoughtlessly.
The key here is the resulting pawn structure. Botwinnik famously asserted that "every Russian schoolboy" knows to recapture on f5 with the Pawn, but that was in a position where Black ends up with Pawns on e5,f5, that are mobile and control the center. In this game White was able to play Bxf4, when the doubled pawns on f5,f4 are static, vulnerable, obstructive and impotent.
At move 10 note that Bxf4 is not yet a threat because it gives up the good Bishop, creates a strong square for you on e5 and sets you up with a K-side Pawn-roller. It also fundamentally changes the position so that your plan may no longer revolve around ..f5, but around ..g5 instead. Why would you free up the Bd3?. Always remember that plans can change depending on your opponents play. In the game, White delayed Bxf4 until after you had played ..f5 and had recaptured with the Pawn, creating that awful self-inflicted Pawn structure.
So at move 10 it was OK for you leave the K-side alone and look for play elsewhere, which you did. Unfortunately ..Na6 does not fit with any long-term plan because you can be pushed from c5 by b4 and end up taking three moves to get to d7. The plan of N-a6-c5 is workable, if you play ,..a5 first.
But also it would have been good to exchange on d3 despite the loss of tempo. This is a closed position and will remain so for some time. Tempi only matter if they can be used to create threats. As Black after 10 moves you have as nice a position as you can expect. Whites play has been sound but unambitious and you can take your time. There is nothing complex here that needs deep analysis. Objectively the game is equal, but psychologically it favors Black because has attack is on the King-side and "mate ends the game"
Which is not a reason to hurry anything. Rather than trying to use tactics to improve the position it is often better to improve the position as much as you can before embarking on tactics. The question is then, are there still ways for me to improve the position slowly? or do I grab at the tactics whilw they are there? A slow approach to the position at move 10 is to play ..a5, Na6, Nc5 and only then ..f5 when Blacks forces are focussing on e4 and forcing some kind of resolution in the center. After this Black will continue preparing his attack with moves like Q-h5 or g6, and Rae8. Attempts at "analysis" are meaningless at this stage. All you need to know now is that there will be plenty to do later on.
