I refuse to get a phone without a headphone jack. Mostly because I know I’m inevitably going to lose my headphones, forget to charge them, forget them in my trouser pockets that will go in the wash. The latter has happened at least a couple of times with my current headphones and they still work just fine. Try that with your Bluetooth pair and let me know how it goes.
Congrats on coming out and being your true self, that was a very brave thing to do.
Your mother, like many parents, had hopes and dreams about who you would become as a person. She’s now being faced with the prospect that those hopes and dreams are dead, that the person she thought you would become is gone. She’s going to need to grieve and from what you’ve written here it seems that process has started. Shock, denial, bargaining, some level of acceptance. I expect anger and depression might show up at some point. It doesn’t necessarily happen in sequence and can cycle too. She’s going to need some time to process, but what’s positive is she’s not outright rejecting who you are, there’s room for her to grow.
My parents weren’t hostile when I came out as gay, but I heard similar things - it’s just a phase. Are you sure? Was it something we did? Where did we go wrong? What will your life become? Over time they came to accept it and told my extended family (including my very religious Pentecostal grandmother). Everyone is now very welcoming of my wife and my parents are delighted to be grandparents to our kids. I know it’s not the same, but there is hope for things to get better, just keep being authentically you.