I lied about dropping my phone in a lake just to get 48 hours of silence, and now I want to vomit

Throwaway because if anyone in my family ever finds this out, I will genuinely be disowned. My family group chat is relentless. It’s non-stop political arguments, guilt-tripping, and seventy notifications an hour. Last Friday after a horrific 60-hour work week, my brain completely snapped. I sent a quick text from my laptop saying I accidentally dropped my iPhone off the fishing dock into the lake, and that I’d be completely offline until Monday when I could figure out what to do. The relief was intoxicating. I spent two glorious days in absolute silence, reading and sleeping. It felt like breathing fresh air for teh first time in months. Then yesterday afternoon, my 67-year-old mom drove forty minutes to my apartment. She looked so worried. She handed me a gift bag with a brand new iPhone in it, saying she used part of her emergency savings because she "couldn't stand the thought of her baby being stranded without a way to call for help." i stared at that box and felt like the most despicable scumbag alive. My actual phone is currently turned off and buried under my winter sweaters in the closet. I have no idea how to undo this without breaking her heart.