Help me find a book about returning home after a long time abroad

[BonCourage]

I have lived abroad for half my adult life now and although I come back to the UK regularly, when I am there I have an odd feeling of a place that feels familiar but unfamiliar at the same time.
I would really like to explore these feelings by finding a book that relects my situation.
I also have a sort of anticipatory homesickness for a time that is about to be lost before it has actually been lost, if that makes sense, as a lot of my elderly relatives and family friends are now dying and I have missed out on a lot of meet ups between family and friends.
It's also not just the people that are disappearing but some of the places too. Every time I go back there is some new development being built, or some old place that has been demolished or renovated.
I notice how much the people around where I grew up in the UK have changed too - it's relatively close to London and an airport so whereas there used to be a majority of people with British heritage there is now a large mix of people from overseas. Please note - I make no judgement on this! It's simply an observation. I too am an immigrant to another European country.
Although I love my new home, more and more I find I am unable to fully settle in my new country, as I am not fully integrated here, but also I no longer feel fully at home in my home country.
I suppose it's just homesickness in the end, but there are quite a few different feelings within the homesickness.
Any recommendations?

Bill Bryson did one about returning to live in the US after a long time away.

Edit: it's I'm a stranger here myself.

Americanah by Chimamanda Ngozi Adichie explores some of those themes and feelings, it's a long read, but a really good one. Maybe also The Road Home by Rose Tremain. Kamila Shamsie's books touch on those kind of themes too, I think. Or maybe a retelling of the Odyssey?

Beyond That, The Sea - about returning to London after being evacuated to the US in WW2. Very evocative of that disconnected feeling.

It's a great book it just suffers a little from not being proofread by anyone English so a few Americanisms pop out of the mouths of the English characters.

Sounds like you're in a good place to write it OP!

A Month in the Country, J L Carr - wistful, loss and restoration.

My first thought which accurately fits what you want was Americanah by Chimamanda Ngozi Adichie but I see that has already been suggested.
Taking the theme of returning home more broadly:
A Little Luck by Claudia Piñeiro.
The Count of Monte Cristo by Alexandre Dumas.
The Country of Others by Leïla Slimani.
The Outrun by Amy Liptrot (this is non-fiction and mainly about recovering from alcoholism).
The Neopolitan Quartet by Elena Ferrante.
Brooklyn by Colm Tóibín.

There’s a YA novel called Back Home by Michelle Magorian (Goodnight Mr Tom) which is about a girl who was sent to the US during WWII and struggles to fit in upon her return to the UK. I loved it as a teen!

Americanah and The Road Home are great suggestions. Maybe more about exile but with that strong sense of place I loved My Friends by Hisham Matar. Currently reading John of John by Douglas Stuart. The character is younger but it is very evocative of change (his mostly) and place. And one from my childhood - Flambards Revisited, Christina returning to her childhood home after WW1 and the social changes of the 1920s.

Thank you so much for these suggestions.
I absolutely love A Month In The Country, it is one of my favourite books and I think some of the feelings it explores are exactly what I was looking for.
Americanah has been on my reading list embarrassingly long now.
I really like the sound of The Road Home too.

Thanks @BonCourage and there is also this way of looking at it: “The past is a foreign country; they do things differently there” The Go Between, L P Hartley

I have nothing to add except I have very similar feelings OP!

The Age of Migrants : Voices Beyond Borders
This book will turn your world upside down—just read it; it’s available on Amazon, very easy to read, and highly memorable.

No book suggestions but I empathise @BonCourage

I've lived in the UK for far longer than my home country now. But sometimes turn into my street and get a weird feeling of being in an alien place.

To me it's like having two lives, still have lots of family and friends back home (and calling it home, does that mean the current country will never be home?).

I don’t have any book suggestions sorry, but part of what you might be feeling is called reverse culture shock.

I have lived in the UK almost half my life and have very mixed feelings about my birth country, where I lived until I was 28 years old. Yet, when back home in England, my adopted country, I sometimes feel I don’t belong here either.

I have just read this article, there is a book called Giant Steps about part of the journey. He recently swam the Channel and it is going to be another challenge for Karl - to be home.

Bushby quips: "You guys know you drive on the wrong side of the road, right?"
His use of the word "you" speaks of his disconnection from home.

World trekker Karl Bushby's final push home to Hull - BBC News

If you are open to non-fiction I recommend having a look at Robin Pascoe’s book about reverse culture shock. I found her books very reassuring when I was in a similar position to you.

Foreign Land by Jonathan Raban. Is the foreign land where the protagonist has been living or the one he's returned to?