This certainly resonates with me...I've long been quite a night owl, very much so in my teens (with long periods where I was sleeping from 5am to 1pm if left to my own devices) and much less so now in my 30s, but each transition–to college or more flexible jobs–that gave me more control over my schedule and when my days would start also coincided with feeling a lot better about myself.
It is not an exaggeration in the slightest to say that many people will treat you badly, joke about you and mock you to your face if you have trouble getting out of bed before 9 or 10am. I thankfully never struggled with depression around it and have had very flexible work schedules, but I can totally appreciate how the circumstances of being someone whose sleep schedule doesn't line up with society's expectations can really wear on a person.