In this game, I tried out an unfamiliar twist and accidently deadlocked several of my pieces in and slowed development. However, I continuously fought to break out of the deadlock. Suddenly, a large-scale piece trade occured and I was able to infiltrate my opponent's position and win the game.

 

 

 

 

 

 

Please give me comments on how I can avoid such a detrimental locked position in the future and an explanation of my opponent's moves. Thank you.

You're lucky your opponent didn't play 8 c5 followed by 9 d6, after which most of your pieces are completely shut out of the game.

3...d6 isn't the usual move. The usual move is simply 3...exd4 when you should just develop rapidly and will have a decent position