If I could work afternoons I could make being a night owl work, but since I don't, I unfortunately don't have that luxury. 8 hours of sleep is also not enough for me, so it is absolutely impossible to have a morning job and get more than 8 hrs of sleep staying up late.
I have been a morning person briefly in the past, and my experience has been the opposite of yours - this is in fact when I was my healthiest, so I strive for that again. Can't really remember how I did it before though other than I was very militant about bedtimes, so I just have to have a strict bed-time policy and eventually I hope it will work out again. The trick is you have to get enough sleep in order to make it work, which is the hard part. Waking up early doesn't work when you stay up till 12 am haha and this is probably why most just give up. Nothing is worse than an alarm clock jarring you awake when you have only been asleep from 3 am to 7 am.
I've also been a night owl most of my life, but I've also been unhealthy most of my life, at least for me, there is a connection between the two and my health. Never been healthy while staying up too late.
I am glad it's working out for you though. I know when I retire I'll probably go back to sleeping in until noon lol.
Another common denominator for me was working out in the morning. Working out at night makes it difficult to go to bed at a decent hour due to the stressor of it no doubt. Maybe I gotta start doing that again also.