From my heart to yours ~ Hiccstrid modern story

Hayden Haddock had his entire life mapped out in front of him, he had good grades, the teachers loved him, he was spending his highschool days playing guitar and day dreaming of ways to get Astrid Hofferson, his crush who had friendzoned him for years. But that changed in a moment.
With hospital treatments, blood tests, doctor appointments and pain, Hayden's life starts falling apart, his friends don't know what's going on, his teachers take pity on him, his grades start to drop.
Can Hayden get through this madness? Can Astrid figure ou whats wrong? Will Hayden even have a future?