Raising a teenage son the way I was raised is not working

My father was strict, I was strict with myself, and it produced a decent officer. So I applied the same to my son. Wake up at 5:30, bed made, no phone after 9, respect through discipline. He is 16 and he has gone quiet on me. Not rebellious, just closed. He does what I say and tells me nothing. Last week my wife told me he had been sad about a girl for a month and I had no idea. I am not sure how to be a different kind of father at 48. I do not want to be his friend, I want to be someone he can come to. Fathers who managed to change course with a teenager, what did that look like in practice?