If you can’t get your book into a bookstore or other retailers, create a “library” with other APSS members and sell it to the stores. According to The Wall Street Journal (July 9, 2018, p A13) London’s Heywood Hill bookstore has casual walk-in customers, “but more than half its revenue comes from assembling libraries for people and institutions… who are willing to pay a bit more in exchange for books tailored to their tastes. It’s a bit like having a favorite college English professor whispering in your ear, making recommendations.” Store staff assemble parcels for readers, many of whom are in the US.
If interested, tell me more about your genre. We can poll other APSS members to help you create a parcel, then introduce it to your local retailers.