How do I learn to think deeply in chess.



Ditto. Drawgood explained it well.
That doesn't mean you shouldn't be able to calculate several moves ahead when the need arises!
Additionally, your thinking should be in terms of safety of your pieces while trying to get or keep the initiative. Most games are lost rather than won.

It's not important to see that far ahead - you need to be able to see ahead accurately in a tree of moves. This is really really not easy.

I looked up your stats with tactics, and I think you’re studying them the wrong way. The pass rate should be at least 60-70%, otherwise it is not efficient because you guess too much. You have to calculate more moves, to evaluate positions better, and to verify calculations mentally. GMs sometimes spend half an hour on one move! Don’t rush things or you won’t see the progress you want to see. Spend no less than one minute (or even two minutes) on your tactical problems. Do not rush things. Bullet/blitz chess brings almost no improvement! At the very beginning you have to play a lot of long games (or at least rapid games), and that’s the best way to improve. Gradually, you’ll see more moves ahead. Yet, sometimes we still overlook simple things, even when calculating a lot of moves ahead. We are humans. Very strong players and pros can play the whole game in their head without looking at the chess pieces. So they have no problem with visualizing moves in their heads. It comes with time. One GM told me it’s easy to reach 1700-1800. I think she’s spot on. But you have to play long games; otherwise you’ll get stuck with almost no improvement.

One more thing. Depending on the position we sometimes have to evaluate it strategically without calculating too much. In tactical situations we have to calculate precisely and spend the necessary amount of time to come up with a very good move.
There are positions that you need to calculate deeply. There are positions that you don't need to calculate deeply. It is from experience and studying chess that will show you if you need to calculate deeply or not. Solve easy tactics problems for pattern recognition. Solve harder puzzles for calculation.
Take a look at these excellent calculation series. Try your best at calculating the positions here. No pain, no gain.
https://www.youtube.com/watch?v=9Kn15YfU8cU