I hear you. I have the same problem. I bought two large book cases at a local department/discount store- floor to ceiling type, five shelf models. I added plexiglas fronts. They promptly filled up.
One trouble is that I like large scale. Love to add the detail, and my mid-seventies eyes and start of tremblings in my fingers gave me the excuse that I needed to build in large scale. I have changed my mind.
I have bought cheap reading glasses to solve the vision problem, and adopted the philosophy of "use it or lose it." I figure I need the challenge of smaller scale. I look in the cabinet and see how many 1:72 planes will fit in the area of one 1:32 model, and how many 1:24 cars will fit in the area the one 1:8 scale car is taking up!
Maybe by actually working on the smaller scale stuff I will acquire the skills and practice needed.