HI Cindy... Your mom and I are probably about the same age.. seems every Judy, Judi, Judie, Judith I hear of are all about my age.. One of those crazy nationwide things..
We had quite a lot of trouble with our basement when we first moved to our home.. we moved from Southern Calif. where there was always a drought going on, to S.W. Missouri where we had water flooding into our home! What a shock!
Once you get your fabric taken care of consider doing some hard thinking about how to make and keep that basement dry. We ended up putting a positive drain in.. there was a perferated pipe around the base of the basement wall to catch and drain off any water that came to the wall..The positive drain took the water out to the street.. we also have the piping under the floor, where any water that comes up from under will be carried to the sump pump. Our water came in under the wall and up through the sump pump. We have since also terraced the back yard where alot of the water came from, made sure the guttering took any run off away from the house, and put in a larger capacity sump pump in. We haven't had water in the basement for years now.. but I'm still gun shy and have lots of sleepless nights during the spring rainy season or anytime we have lots of rain.
I also run a dehumidifier from early spring until late fall..
Another thing you should consider is bringing your sewing machine(s) upstairs until the basement problem is taken care of. All that moist air is not good for machines. It will ruin them in time. Also bring up any books.. they also draw the moisture out of the air and will mold or just get musty smelling. A LOT of work.. basements are wonderful, I don't think we could live without one now.. but they are a two edged sword, and are always a worry.
I wish you strength and stamina, good humor and help. Keep on, you and your stash will get through this!