Girlfriend likes to text and drive. I don't know how to make her stop

My [M17] girlfriend [F16] recently got her license and for the most part is pretty good. Recently, however, she's started texting/snapchatting while driving. She has a history of self-destructive behavior (she's been diagnosed with depression) which really concerns me. She's gotten way better over the past year and I've done my absolute best to be supportive and help her. I've asked so many times to stop doing but it's always the same thing "I don't do it when there's anyone else on the road and I don't care if I die or get hurt". Today she did it again and I finally lost it. I told her that if I find out about it one more time I'll have her mom take her license. She pretty much said she doesn't care if she dies and I told her that I loved her too much to let herself do that. She immediately came back at me with "if you loved me you'd help me more mentally instead of threatening me knowing that I don't care if I live or die" and "threatening makes you no better than [abusive ex]"

I haven't said anything back yet and I really don't know what to do here