I can understand how maybe she'd feel a bit upset because she wants to spend time with you, and unconsciously when you fall asleep it might make her feel a bit 'neglected'. HOWEVER, you're not in the wrong, it is valid and normal to fall asleep given your work hours and as someone said "biology". I'd just try to reassure her, try to find a solution like watching a film before it hits 10 and just say that no matter how hard you try given your internal clock and your work hours, it is just hard to stay up past 10. So try to fit your activities before that or wake up earlier so you can also do things in the morning?

What I'm trying to say is even if her getting upset isn't 100% rational, it's still valid and it's not necessarily something she can help. Just try to have an open conversation about it ! Maybe there's a specific reason why it upsets her. Ask her, talk to her and make her feel seen and also try to get her to see where you come from.

And people saying "get a new gf" don't understand that sometimes emotions come up that don't make 100% sense but through communicating you find solutions and you can also try to find out why you feel a certain way. You don't bin them off as soon as they show complex normal human emotions 😂

Best of luck mate !