WAV - you define immigration (or if you prefer THE ACT OF IMMIGRATION ITSELF) to exclude yourself.
Therefore, 'immigration' means 'the immmigration of people of foreign ancestry'.
Therefore, you feel English culture is threatened by the arrival in England of people of foreign ancestry.
Therefore, what you're expressing is precisely

"prejudice and antagonism towards people of other races, especially those felt to be a threat to one's cultural or racial integrity or economic well-being"