Yeah, these are also my usual sleeping and waking times, and I've also had that since I was a child. I almost don't know how it feels to go to bed because I'm tired from just the day, it usually happens either because I've been doing something exhausting or because I'm jetlagged. My day/night cycle also seems to be way longer than 24 hours, so if left alone without any willpower, I tend to drift and sleep later every day, until I sleep in the morning, Kajiura-style, and decide to do something to fix it. I never dared to see where (and if) it would stabilize.
For two years I tried working in an office under a "normal" 9-to-5 schedule. My daily commute was also only 15-20 minutes long, so I was lucky. I still never managed to feel really awake before noon, except the semblance of consciousness that you described. What's worse, I was suffering from headaches and exhaustion, like Wikipedia sensei says, especially during the winter, where inadequate daylight made it much worse (the lack of proper daylight seems to influence me much more than the average person). I was basically a zombie on Thursdays and especially Fridays and I was longing for Friday night, where I could sleep 12 hours. I am now working remotely and my working hours are fairly flexible, so I'm much more productive. In university I often just skipped first term. In school we had afternoon-only lessons every other week, so it made everything much more bearable. However, in the morning I'd often fall asleep during class, and even have Kajiura-style long dreams in the few seconds that I was asleep.
My first semester of Japanese classes was also in the morning, 9 to 11, because I started late and all other classes were full. Needless to say I had missed almost half of my lessons and it took forever to catch up.
BTW, I have downloaded the "Sleep as Android" application on my phone, which I found to be extremely helpful during my office days. You can configure it to allow up to a certain amount of snoozes, and also to not stop ringing unless it scans a QR code, which I printed and placed in the bathroom. It can also try to wake you up at the end of a sleep cycle, but that never works for me, I never fail to be in my deepest sleep early in the morning. Not that I'm really awake after going to the bathroom and brushing my teeth (what shower? I shower during the night in order to gain these 5 minutes in the morning), but once I've done that, I've gathered enough consciousness to not "go directly to bed, do not pass Go, do not collect today's wage".