My therapist wants me to explain my Spirituality to her and I don't have a clue
Just substitute "philosophical / existential beliefs" for "spirituality" and you'll probalby be fine.
If she is pushing for a particular spirituality, find someone else. But she's probably just trying to figure out how not to offend you / step on your toes needlessly, and how to frame her advice in ways that you can accept and relate to.
Personally I'd just say that I'm a philsophical naturalist and an agnostic atheist and a skeptic. That is concise and pretty much covers the territory.
I just posted on the spirituality topic, I was noticing the difference between what I use for the benefit and what I believe. I don’t believe in an outside force, it’s all in the mind but still ok to “be” with that as long as you know the difference. If you have no idea that’s what you should say. I’m trying this app instead of therapy cheers