I got doxxed and I don’t know what to do

I recently downloaded a "buy and sell" app because I was hoping to buy. Talked with a seller (male) with good reviews and I communicated smoothly with him to which he agreed to let me see the product first and get it delivered before I pay in full.

The item never got handed over, the item was never given and his WIFE messaged me, insulting me over text, her last text being "okay, you do you :)" very passive aggressive... the seller apologized for his wife, saying she had come up with the "payment first" policy and had stated that she had bipolar disorder.
And that they ran the account together. Additionally, at the time he wasn't home.

Around 40 minutes later... my phone lit up with messages, calls... all about ac installation and fixing. I was confused, answered a call and politely asked where they'd gotten my number from. I found out that my own number was posted Facebook group and even the nickname I had put for myself on the buy and sell group was there.

Someone is currently impersonating me on Facebook and I feel completely helpless because some crazy woman decided to put my number up on the internet.
I have no idea of any admins in that Facebook group, and yes, I've reported both the post and user but Facebook notoriously does absolutely nothing. I feel a lot of anxiety over this and I don't know what to do... especially since the fake account is still alive and running.