I would definitely suggest a ground-type- which you seem to be working on, so good- or something with Volt Absorb like Lanturn or... Uh. I don't really know what else works for that, oops. If Gyarados is actually useless I might also suggest ditching it for the time being; Bidoof too, since they're obviously not doing you any good. Better something else than something that will just outright die anyway.