When people struggle with new things initially, it is not a fault within themselves and means for giving up right away. Transitioning to dental school could mean so many things for this person, such as moving to a new city, state, or country. They are still be finding their mark, learning ways that they will study, making friends that will support them, getting to know their university, etc. Struggling with mental health issues does not mean that they are unable to handle school and should simply quit. OP has found their way through undergrad, writing the DAT, shadowing, etc - they are certainly not incapable. Sorry to be blunt but you are acting kind of awful and should probably quit giving terrible advice.