SCHAUMBURG, Ill. — Linnea Sorensen falls into a funk whenever her girlfriend of four years leaves for her six-month stints with the Marines, and the high school junior has trouble concentrating on her class work. “I’m somebody who struggles with my mental health quite a bit,” said the 17-year-old, who attends school in this suburb of about 77,000 people northwest of Chicago. “When you’re in school and not fully mentally there, it’s like you’re not really grasping anything anyway.” Now Illinois is giving Sorensen and students like her a new option for dealing with mental health lows. The state …