Why i don't have photographic imagination while delivering mate

At my level in rapid chess photographic imagination is more important than photographic memory. By that I mean I cannot imagine in accurate detail the next couple of moves after sacrificing a piece in photographic detail. I seem to don't have imagination and predict the future after 4-5 moves after a brilliant sacrifice which was one of my candidate moves. To tell a coincidence whenever I think of a sacrifice during a game the computer always gives a nod after post-match analysis. Because of that, I miss many of my brilliancy which would have been great if I deliver. It seems like I don't have training in this part of the game. Can somebody show me how to overcome this defect? Any type of little help is welcome. If you want I can show you one of the games.

Here in the first image I miss a knight sacrifice g5. If he accepted it, it would result in picture perfect mate

Here in the second image, even though it is complicated I did not have the guts to sacrifice my dark square bishop at h6. I would be very thankful if anybody shows me why is that happening to me. The point is that you do a rook lift to end the game after 4-5 moves. I completely miss that rook lift. I don't whether that is imagination or lack of understanding of the advance concept. Anyway, I lack something that's point of the thread what to do about that.