Judging from your previous posts it's fairly clear you were rejecting multiculturalism. I'm white and would fill out the census in this way however I think it's unacceptable to hold 'white' as an identity. I do not consider other white people to be kin in the same way you appear to. It's not possible for any policy to be anti-white and white people do not experience racism.
White is the label given to the archetypal member of society and has a changeable definition.
Civic identity as an American, Kurd, Belgian or whatever is fine as long people can join your society and be accepted. Local identity is positive. Ancestral Irish, German, French traditions if you have them are wonderful.
I'm sorry you lost your identity but most of the rest of us, be it, white, black, or asian have thankfully not. You seem very clingy to that word "white". If it helps you can say Caucasian or pink, or Aryan (though that may have some negative connotations). It's all referring to that one race of people that stemmed from central Eurasia many millenia ago. Maybe you want to refer to us by haplogroup...R1a, R1b, J?
Let's use your Belgian example. That's a nation state and the ethnic groups that created it are the Walloons and the Flemish. They also happen to be part of the race called (R1a, R1b, J, I1a, I1b, K, G, E3b, N, & Q). Shoot, it seems easier just to call them white.
I'm just going to mostly ignore that you just posted a crazy thing like whites don't experience racism as I have personally been affected by it multiple times, but I think it's because you have a bastardized hyperprogressive definition of racism.
Also, I haven't been called white as much as I have when overseas. You seem like someone that's been pretty sheltered. I'm guessing you don't venture much out of your diverse city like Chicago or NYC? I've been to over 60 countries and there's nothing like being gawked at pointed at in places like Tanzania or Bangladesh when you are a white person and I have never been called a white person so many times. Looks like those dastardly Europeans convinced them I was white.