How do I get through the rest of Kanto in Pokemon Heart Gold?

I can't seem to find my through the rest of Kanto. I'm not allowed to go to Viridian City through Victory Road, I can't yet enter Cerulean Cave and there are construction works blocking my way to Route 19. My friend asked if I had fixed the generator: yes, got the magnet train pass: yes, showed Bill's grandpa the required Pokemon: yes, beaten the Elite Four: numerous times, fought Suicine: yes. He fainted, but yes. I have also been fighting all the gym leaders I can reach in Kanto. The only places I can't get to are Seafoam Islands, Cinnabar Island, Pallet Town, Viridian City, Viridian Forest, DIGLETT's Cave, Pewter City, Mt. Moon and Ceruclean Cave. My Kanto region map only has Cerulean City, Saffron City, Celadon City, Lavender Town, Vermillion City and Fuchsia City available. I've beaten all of those gyms. What do I do? This is frustrating and I've been working on it for weeks.�