Agree, you need to see a counselor TODAY. Don’t wait til next week; it’s Friday so you need to go now. Skip the sports practice - let coach know you aren’t feeling well (no need to be specific).
You are at Harvard and playing a sport - you are not a loser! You will see, many of the “cool kids” from HS will not do much with their lives. Everything changes once you become adults and “the geeks rule the world” (there’s a book with a similar name).
I had a friend who was a lot like you in HS/college. She was valedictorian and went to an Ivy. She didn’t feel like she had strong social skills. But she did start making friends at the Ivy - finding her people - it takes time. You are only 4-6 weeks in now. Give it time and take care of yourself! Drop the sport if you need to. See the counselor regularly. My friend is a successful adult working in a field she loves. She married late to a super nice guy.
Please just walk over to the counseling center. They are familiar with this - you are not alone - others feel this way too. They know how to help you.