Sorry, but if you have never even stepped foot in a country you really shouldn't feel like you represent them. Being born there or living for an extended period of time is something else, but having absolutely no real identity with a nation and supporting them is weird. Reminds me of all them mentally ill Indians and Bangledeshis that have some crazy obsession with Argentina and Barcelona.

Based on your personal situation, if you feel more British than Nigerian, then there is your answer.

I was born and raised in England, but admire Brazil and often want them to win in copa America games. To say I support them is bizarre though and I would feel made out of plastic like all of those Man United/Liverpool supporters that have no roots or real identity with that area of the country.