My girlfriend smells so bad I can’t take it anymore

I don’t know what to do. My girlfriend shower 3-4 times a weeks. And doesn’t brush her teeth at night until I remind her. I’ve given her time and room to develop good hygine habits. I’ve bought her nicer toothbrushes and shower gel and body wash. She never wearsunderwear and when she does she only wears them once. I’ve thrown them away blooms of dirty underwear from her room. I’m seriously considering breaking up with her if she doesn’t get her act together. Any advice how I can approach this to her without being offensive.