Make friends with fellow interns.
No one will sympathize with you more than the other people in the trenches. Chances are you won't be the only intern working. So why not make the most of it and take the opportunity to reach out and see how you can help each other? All real jobs rely on a balance of teamwork and independence, so it's best to start developing your "professional self" at an internship. Maybe you don't know where a certain building is or haven't found a good lunch spot—ask an intern who does.