Yes, I do get how you feel and I feel the same though for different, but also complex reasons. I am non-British by birth (but now a dual citizen, so technically I'm British). I'm white and 'look' British, but I obviously have an accent so people know I'm not from here when I open my mouth.
My dad died when I was 18 and I am NC with my mum, who still lives in my birth country. I have no family in the UK other than my children and dh's family. I have no relationship with any family in my birth country, as aunt/uncles have all died or I was never close to them to begin with, so last saw them years even before I emigrated.
My sense of a loss of connection is not so much to the culture, though the culture is quite different (and frankly, fairly alien to me now as I've lived in the UK for so long), but is about the loss of family connection/stories/traditions. I have only a few sort of tangible 'things' from my childhood. I have some toys and some childhood photos, a few family heirlooms. But I don't have any of the stories anymore. Stories about my childhood or what my parents' childhoods were like or about ancestors, about places they lived, where they are buried, genealogy, health conditions, etc. all of those sorts of things that are passed down verbally in families, I don't have. My dad died suddenly and my relationship with my mum was fractured quite unexpectedly (due to something quite harmful that she did to my dc). If I had ever expected things to turn out the way they have, I would have sat her down and asked these questions and collected all these stories. But I didn't think I needed to yet, and then once everything happened, it was too painful to go back and ask for all of this information (it would have been used as a manipulation tactic, even if I had).
I would like to take my dc (and dh too) back to my birth country one day, as none of them have ever seen actually where I grew up (we've been on holiday to a more 'touristy bit' but that's it). But even doing that, it feels a bit context-less. Like I have my own memories of these places, but I am lacking a lot of the family history and the present day connections to them. There's no grandparent to say, this was where I grew up, and this is how it was different back then, and I have this memory of your mum when she was your age and she did this. If that makes sense?