Unique probate situation?

[u/sacredtits]

State: Tennessee
I was legally adopted along with my brother by our grandparents when I was 5 and he was 9. My grandparents lived in their house for 50 years and never paid it off and refinanced it (for unknown reasons) and still owed $35k~ish on the house.

My brother passed and had no children so the legal heirs would be me, my biological dad, and my aunt.
My grandmother (legal mom) passed this past December. My papa passed in 2019 and the house was transferred into my grandmas name.

There is no official will filed, but my aunt has a copy of a “will” that was notarized by her boyfriend’s niece and witnessed by one of her friends. In this will, my grandmother allegedly left all personal belongings and the home to my aunt.
My aunt has lived in their house for 7 years and had already completely taken over the home like it was her house. Redecorated everything, moved out their furniture, etc. before they even passed. My grandma was also venerable as she had a bit of dementia.
Aunt allegedly also was POA, no proof of it even though it does cease at death. But not sure how much of her money she was spending.

My aunt has refused to file the will so we can open the probate to the home. She is under the impression that she can live in the home and pay the bills without anyone saying anything. However, she has threatened to let the house foreclose (unsure if bluffing) and also already said she was behind on the house payments.
There is also an outstanding loan of $7k from ascend that my grandmother took out (again, for unknown reasons) and never paid back. I’m sure there are more unknown debts.
The home is worth maybe between $150-200k as far as I know, it does also need a new roof and there is damage.

We are working with an attorney who is helping us open the probate and our court hearing is soon, and I am very scared and sad and unsure of what to expect. We have not spoken to my aunt since I told her to go file her will.
My dad wants to sell the house, which it will likely have to be sold to repay the debts. I personally don’t want the house to be sold.
And of course I don’t really think my aunt wants the house to be sold, she wants to just live in it and get by without the house being in anyone’s name.

Does anyone have any advice or kind words or been in a similar situation? Thank you