The annoying thing when it comes to this kind of sleep problem is that it never gets completely better. Over time I've come up with ways to ensure I actually get up early enough for important events and don't sleep through alarms - not even 'i hit the snooze button' problems but just alarms literally not waking me up - whether it's by making alarms louder, setting 6 alarms spaced out 15 minutes apart (yes, really), or going without sleep if I have to wake up too soon (in practice I found that getting 3-4 hours of sleep consistently is impossible; I always sleep through the alarms).

Even with all that though, nothing really changed. If I go a week or so without setting alarms and just let my body wake up naturally after a night's sleep, I will naturally drift from waking up at say 6am to waking up at 11am. Sometimes I drift backwards, and find myself waking up in the dead of night at 4am and being completely awake. It's extremely valuable to be in a work environment where you can at least mitigate this by going in to work early some days and late others.

I also find that forcing yourself to adhere to a sleep schedule that doesn't feel natural can result in more fatigue, and I wonder if other people have the same experience. I tried doing an 'early' schedule at work a few times, waking up at about 6am and heading in to work early, and always found that I was completely exhausted by 5pm. Moving my waking time forward a few hours almost always alleviated the problem. Maybe it's something you get used to only after doing it for months at a time?