@SheilaKathy - I am going to throw my two cents in - and as with all things, take it or leave it, truly.
In my opinion you escalated into hyper vigilance very quickly, perhaps even in advance of the first meeting with your pastor.
You acknowledged your own reaction to the pastor responding: instead of managing the stress of waiting, you escalated into worst-case scenarios.
I do understand that you want to support yourself by getting into an environment where you can work with children. But sometimes, we have to take things in steps. If what happens is that you end up in a role helping the other adult volunteers who supervise the children - then, that's a necessary step along the way, as determined by the person (pastor) who has ultimate responsibility for the kids.
I would encourage you to re-read this thread and do not dismiss your trajectory within it as venting or blowing off steam, simply because the outcome has turned towards the positive. You got very upset and struggled with managing it.
Now, that's a human thing, to be sure. But because you also have compound mental illnesses (bi-polar, and PTSD, correct?) you need to take seriously how stressors affect your system. Again - everyone should, but those of us with stress or mood disorders really can do ourselves some damage - and in turn, do damage to others.
There is something about your journey through this that reminds me of times I've allowed myself an unrealistic sense of my own capacity, and also times where I've gone into a bit of a magical thinking mode, that if I could just add x, or y, or z to my life - everything would be so much better.
I also think that the church, as a private entity, reserves the right to ask anyone anything at all about their background before accepting their volunteer services - whether it's for VBS or housebound parishioner visits. That's not discrimination, it's responsible management. The individual has the parallel right to disclose nothing and withdraw from consideration. Both sides are protected and enabled.
Public institutions operate differently - but still, no-one is required to accept any volunteer just because they really want to be there. Employment laws are entirely different.