Won't Stop Until I Surrender

In the year 2020 things have gotten a little out of hand. First there was a sickness that wiped out a quarter of the human population. The government has completely fallen apart and most of North America's people are living on the streets with little to no food or water.
However scientists believed that they have come up with a cure for cancer but somehow there was a toxic explosion and everyone in the building now possesses zombie-like symptoms, only they aren't completely zombies.
16-year-old May Rose has no idea on what is going on until she finds a nasty surprise at home.
She runs away and bumps into 17-year-old Tristan Winter who had just found out the same thing. Together they run for the hills because the city is hell.
Will May be able to survive the apocalypse and save the ones she loves?
But what happens if she finds out that the only way to stop it is for every living thing on the earth to die?