Being expected to support myself financially from a young age stood me in good stead. Some stuff from my childhood sucked, but I - um - read your "you want to be on your own, so this is reality" paragraph with relief. It seems to me that huge numbers of parents make their children dependent on constant subsidies rather than the occasional helping hand for a project: and those kids take forward a dangerous sense of entitlement and unkindness towards the world.
My best friend who was a recovering alcoholic and the most wonderful person who I've ever met - she always "got" boundaries yet her reaction under pressure was always to smash them up - until, much later through much therapy, she arrive at a different awareness of herself. I marvelled at her humanity but also was used to anticipating the boundary-smashing phase until she fought through it.
I would be a terrible parent - a raging insomniac and too reclusive - but I think what you are doing is a gift to your daughter and you know that - but sometimes emotional learning is exhausting.
You are doing so well to hang on to your own recovery - high five and respect for your perseverance and courage. Can you, somehow, shower the kindness and love on yourself right now. Your struggle is worth something (not sure if what I've written makes sense).