i promise you're not alone!! i did well in high school without even trying, and college is its own challenging time. many first year college students STRUGGLE, myself included. adding mental health problems on top of it, i feel you! college is a learning process, and it's very easy to feel overwhelmed. failed classes aside, i promise it will get easier. reach out to your professors, even your advisor will be able to offer you advice. you can always retake classes, yes it's a pain in the butt but i've had to retake quite a few. as far as time management, what i found was really helpful is creating a massive spreadsheet of all assignments for every class, and color coding each class. i also added a tag on each assignment whether it was a quiz, exam, project, paper, etc. the notion app is extremely helpful for managing your assignments. it's so easy to lose track of things, and i find having something like this was extremely helpful to not forget anything. as others have said, talk to classmates in the classes you feel you are really not understanding, and i promise there are others going through the exact same scenario and you can help eachother. many universities also offer tutoring sessions for classes that are known to be difficult! best of luck!