Please Help Me With the 18th Move

I must face a hard decision on move 18, whether to promote a pawn chain e4-f5-g6 with a light-square bishop or to maneuver g6 to f files. So, I tried the second method and was able to do it, although I could not queen it.

After 10.g4: this wall allows me to have more space develop my pieces and put black into a cramped position.

14. Qd4: replaced my dark-square bishop with a more powerful queen. When I visualized ahead my complete formation, my bishops will be less active than my knights, so I did not hesitate to trade it for a knight, which to me was more active than my bishop or his bishops. Well, when I reached move 18th, I was a bit worried about transform my game without this bishop.

 A difficult situation for me because I was a bit nervous. I put so much effort in this game to carry out the theories I learned today about the 4th rank and pawn chain so I did not want to ruin it. 

I did not go this way for 2 reasons:

1. He did not castle so if I mobilize my force to kingside but he castled queenside then it would be a very bad situation for me, I believed.

2. I wanted to centralize my rooks for both defensive and offensive purpose because his guns are pointing at my queenside.

So, I decided to maneuver my g5 pawn to the f-file, which means that I need a lot of preparatory work. I know that I need Bishop to anchor my pawn and at the same time prepare for an outpost at e6. I also know that I need Rook to support it. So, I managed to form up this formation, of which I was very proud.

I must sacrifice my Knight the maintain the advantage.

Finally, an outpost. I planned on doing this because I wanted to apply what I learned and also, it was the most logical move to me. 

The outpost did not last long because I faced a serious decision. I must initiate the trade because if I did not, the result would have been awful to me as below:

26...Bxe6 27.fxe6 Rxe6: I am losing

The rest of the game, things were out of my hands but I did manage to make the machine resign. So, hopefully, I will learn from you guys on how to improve my game from move 18th.

Thanks

18.g6 is easy.

Candidates for black are 18...0-0-0, 18...fxg6 and 18...f6

18...0-0-0 or 18...fxg6 both get wrecked by 19.Ng5 or 19.fxe6 Bxe6 20.Ng5 respectively.

f6 allows a pawn to stay entrenched on g6 and after 18...f6 19.fxe6 Bxe6 20.Bb5+ 

Blacks candidates are 20...Nc6, 20...Bd7 and 20...Kd8 (20...axb5 21.Nxb5 Q~ 22.Nxd6+ is busted)

20...Kd8 king cant castle and position is dominating no further calculation required.

20...Bd7 21.Nd5 Nxd5 22.exd5+ Be7 23.Bxd7+ Qxd7 24.Rhe1 is crushing

20...Nc6 21.Nd5 this is obviously bad for black, I'm done calculating.

WOW! 18. g6 IS EVEN MORE POWERFUL!