@SarahGen-- You might want to change your hand soap. And are you using a hand lotion regularly?
Most of us don't realize how drying hand soaps can be. Liquid hand soap usually has alcohol in it and on top of it, I use hand sanitizer frequently. If you also wash dishes by hand, that will dry out nails too. All of this adds up to dry, brittle fingernails that break very easily.
Try to use hand soap with a moisturizer in it and use hand cream after washing your hands. Don't use hand sanitizers too much and wear gloves when washing dishes and so forth. See if all this makes a difference. It has made a difference for me.