Tophers Ton by James Noll

The end of the world comes in a barrage of bombs, a rush of tsunami, and a hail of meteors. Topher, still recovering from his kidnapping by a deranged serial killer, manages to not only survive, but nearly rebuilds civilization. If it weren’t for Rasheed, the demented boy-god with a tank, or Nurse Smith, the deranged leader of a group of crazy doctors, or Liam Chris, a deranged despot seeking revenge, he might have been successful.