Being in the same situation in a different country, but a couple of years older: In my experience you never will be fully accepted by everyone. You will be the Polish guy in UK and the British guy in Poland.
You can identify yourself as what you want. You must learn that people have the right to have their own opinion even though it is wrong or opposed to yours. You have to learn not to care and live your life as a nice person. It doesn’t matter at all what others think as long as they don’t hurt you.