Some high school kids have a lot of support from their teachers and parents without asking. In college, you have to ask for the help, you have to follow up, YOU have to recognize when you are in trouble.
I’ve known a couple of kids who could have kept up with the academics but not with all of life - the doctors, the medication, the getting a bad night’s sleep and having to compensate for that, with overloading on the social activities and still needing to get up for class.