In the winter soil mealy bugs can be a problem for African violets.
The African violets get less light, the soil stays wet for longer times and it’s chilly by those windows creating conditions for soil bacteria and bugs to grow and attack.
The plants begin by wilting and the leaves appear to be thinner. This can mean root rot or soil mealy bugs are attacking your plant. Either way the best course of action is to repot your plant. It is the bacteria in the soil not the water that rots the roots. So either the bacteria or mealy bugs need to go.
Unpot the plant and check for mealy bugs, you’ll see little white spots in the soil at the bottom of the pot if you have them. If not it is bacteria that is the problem. When you unpot your plant gently remove all the soil from the roots, cut off damaged roots and rinse the roots thoroughly but gently in running water.
If when you unpot your plant you find the roots are short and all near to the surface that means you’ve been over watering your violet.
Buy some fresh soil at your local nursery and run your pot through the dishwasher if you wish to reuse it.
And remember as long as you have one healthy leaf you can root you have not lost your African violet.