Whew! It's okay.
I have a starter I captured using the method in The Cheese Board Collective Works book (similar to the one in BBA). I have had it for about six years now (it is almost the same age as my daughter). I haven't been baking a lot recently and it sat in my fridge for a while. I took it out to refresh it last week and got almost no growth. I was afraid I had killed it, but when I got up this morning I found that it had grown to about 1.5 times its size. I was so relieved.
Thanks for listening. I just wanted to tell somebody who would understand.