The people on here aren't trying to lecture you, they are trying to give you good advice that could save your snakes life. By the sounds of it this type of injury is NOT one that you could treat at home. If you tried he would most likely lose his eye and probably would get an infection in the eye and the head wound.
Please take him to the vet and if you can't pay them right away most vets will take payment plans especially if it's an emergency.
PS- bad rat bites can send PEOPLE to the hospital let alone a snake that gets hit with a bite on the face.
