my application for renting a house got approved! why on earth do i feel so scared and sad?

this is what i have been dreaming of for the past 6+ months.

i found a roommate and a cute little affordable house to rent with a yard and a garage and (mostly) hardwood floors. my move in date is in exactly one week. and yet i feel immense, crushing grief.

i want this! i NEED this! i love my family but oh boy certain family members are most of the entire reason i'm in so much therapy anyways. living (still in the same city as them) independently will allow me to be ME in my own home without hiding what i am reading and thinking and listening to or who i include in my close friends or how i practice my faith. i will get to sit in the living room and won't have to listen to see if a parent is coming home drunk and belligerent. i won't have to hide health insurance statements. i won't be made fun of constantly for existing in my physical human form. i won't be sexualized and infantilized in my own home!!!!!

but i feel SAD.

i know my parents don't want me to move out, but that can't be all??

where is this grief coming from? has anyone experienced anything similar? what do i do with it?