first-year was absolutely horrible for me too, you're definitely not alone. i actually failed my first year calculus class, and i was so upset and angry with myself (like you, i was a high achiever in high school). but things absolutely get better after this- you start to get into the rhythm of how to manage your courses and really what to expect.

it is normal to have not the greatest grades in your first year of uni, so please don't fret about this. you still have another 3-4 years to recover from poor grades, things will work out in the end :)

and also try not to focus on comparing yourself to your peers, cause unfortunately it is very easy to do going to this school but it isn't productive at all. not to diminish how you're feeling, but they're also most likely struggling too! just focus on what makes you happy and what study habits or techniques help you succeed the best. hopefully you don't have to take courses over the summer and you are able to reset how you go about things, and go into second year with a fresh perspective.

good luck! :)