Does anyone struggle with excessive sleeping?

I am really struggling with excessive sleeping, I don't know why. I don't have any medical conditions other than my Autism and low B12.

I wake up at a usual time, around 8am but feel very dazed and fall asleep again until 10:30am and then stay in bed scrolling on my iPhone until around 1pm.

I'm trying really hard to improve my life and change things, but I feel exhausted and need lots of sleep. I used to be able to sleep fine and go to bed at a good time, but recently I have been resisting sleep so I don't fall asleep until around midnight or 1am.

There's a lot to unpack there, I'm feeling a little lost as I can't see many posts relating to excessive sleeping and Autism.

Any advice or personal experiences would be welcome, thanks!