Novel after ten years' absence.

These days, Lately I am have been reading Banana Yoshimoto's novel again after ten years (just a suggestion - your original is ok, but a little ambiguous) have elapsed absence.
I still have some of her books, because I used to read her often when I was teenager, and I did not throw them away still now.

I found one particular line in this book, maybe I underlined the words by myself and didn't remember doing it.  But it was so such a nice phrase (what was the phrase?). It was about things that are always in my thoughts I am thinking every time.

I thought feel I am have not changed much in these ten years ago.
Of course, I have had so many experience in these years, but basically, nothing has changed.

Novel after ten years' absence.

These days, I am reading Banana Yoshimoto's novel again after ten years' absence (or "after not having read it for ten years", both work but this sentence may be more clear to the reader :)) .
I have some of her books because I used to read them when I was a teenager.
Still, I did not throw the books (or "them") away still even now.

I found a line in this book. Maybe I underlined the words by myself, I don't remember doing it.
But it was such a nice phrase. It was things I am thinking every time. (This is a very complex sentence! To make the meaning more clear you could say: "I think this every time I read it")

I thought I am have not changed from ten years ago.
Of course, I have had so many experiences in these years.
But basically, Nothing changed.

Good job! This is a very complex entry. I am impressed by the ideas you are able to express in English :) all these little errors will be easier in time :D