England, Scotland, Wales and Northern Ireland are constituent countries of the United Kingdom. The United Kingdom is also a country. You can disagree, but you're disagreeing with the government and the international community.
Scotland, Wales, and NI have their own parliaments at least, so from a constitutional perspective one could argue England is not a country but a state, but that is only one narrow definition.
Not a problem, I disagree with the government all the time. Scotland has less sovereignty than US states, it's not a country.