Daycare, well, there you go.
We have had all sorts of sexual thoughts that I find uncomfortable to disturbing. None of them involve children or us doing bad things to other people but they do revolve around bad things being done to us. The thoughts are reenactments of things that were done to us or they're derived from those events. We know the function, for us, of the mental replays is to reduce the terror, rage, embarrassment and confusion. That is built in to how and when the tapes play and the evidence of them being replays are the content and our memories that match or parallel that content.
Early on I didn't remember all the abuse events but after some of what I recalled began fitting in place, I knew it was only a matter of time until I remembered the rest. I'd read so many biographies and autobiographies about people with DID that this was predictable.
For people with DID, 99% of disturbing sexual thoughts or fantasies are likely to be a direct or indirect result of sexual abuse. Starting from this likelihood should help you put aside at least some of the fear, guilt, and shame and enable you to hold some compassion and understanding for yourselves.