I used to do the same and over the years I acquired hundreds of books that I never read. I don't want to think about the money I spent. When we decided to move and downsize our house I decided to address my books, I decided to only pack what I thought I would realistically read in the next 2 years and anything I needed for work. I only packed 2 boxes of books. Which left me with about 800-1000 books to deal with. I sold, gave away, and donated them all. I had at least 4 large bookshelves that I also got rid of.

Now my rule is to not outgrow my single small bookshelf. It's been 3 years since my move and this year I'm committed to reading the last of the books I brought with me.

A few things that have helped me not overbuy books since the move are: I decided that buying/collecting books is a separate hobby from reading and it was not a hobby I want to participate in. I know myself well enough to accept that I like "fresh" books, I lose interest in books once I've owned them for a while, there is always something more interesting to catch my eye. I'm a sucker for a cover or a display, so I don't spend much time in bookstores.

I get most of my books from the library these days. I'm retired and have a lot of time to read and between physical books, ebooks, and audiobooks the library keeps me very well supplied.