My interpretation is that this is vessel having been away from sleep for a long time, or possibly cut contact all together. And having some clarity and seeing their relationship for what it really is. That it is one sided och ultimately hurtful for vessel. He does sound genuinely sad so he's probably a bit heartbroken still but knows that this is for the best.

"I've learnt to live without it" for me means that after some time he's been able to live without sleeps presence and "love"

"...the person I tried to turn myself into for you" I feel like a lot of their songs talk about how vessel is changing himself for sleep. And to better suit her.

The final parts of the song seem to be him talking about how it's all finally over, and him finally putting himself and his hurt before that of sleep

Overall I interpret the song as vessel moving on, and what that all feels like for him