Someone has hacked my phone and is sending unidentified information almost daily to several unknown numbers without my premission. What can I do to stop this immediately?

I have recently discovered the same thing.  My Tmobile Usage Log is showing 769 text messages since October 20, 2024 & today is the 26th.  Almost all of the texts are to/from numbers that I don't recognize.  It was discovered in January that a law enforcement employee in communications who has been stalking my children & I had hacked my online accounts.  Even more concerning is that there are THOUSANDS of texts going from my Tmobile cell phone number to my daughter's cell phone number that neither she nor I sent.  These texts are literally every minute.  This began hours after my transgender child was allegedly found by Burlington NC Police Department officers unconscious, bleeding, & with a shoe print on their chest & had been urinated on at a church.