Story time!
I got into magic around late July of 2014. 9 months prior, I came back from Afghanistan a complete wreck. Upon finding magic, I also happened upon cardistry and set down both paths.
I noticed after I started to get marginally okay at Charier and Revolution cuts that my anxiety was a bit lessened, especially in public (where I would do this). The missus and I figured out that because I had to be pretty focused into what I was doing with he card and the constant repetition, that I would gradually calm down enough to compose myself again. However it didn't take a whole lot to get the anxiety going again. So, the cards came out again.
I stuck with one-handed moves for a couple reasons:
1) they draw more attention to themselves. I was doing flourishes to try and drown out the outside world. If I go and do something like Cylinder, strangers would be more invlined to approach me and ask what I was doing. The exact opposite of what I want.
2) my left hand was just in bad shape. At the time I have osteopenia (which can evolve into osteoporosis if it battles enough Pokémon). And I would later find out that my left wrist was broken 3 times in the span of a year and a half (I never knew). All I knew was that my left hand was painful and I couldn't use my thumb in a way to accommodate most flourishes. So I just learned everything for the right hand.
When I went in-patient springbof this year, they had a deck of cards (a super dingy and super bendy Cartamundi deck) that I was flourishing like crazy when no one was using them (even though, due to the condition of the cards, I could only do about 5 flourishes).
There you have it. Great distractive tool, and keeps me focused on something that doesn't trigger the anxiety and fuel it further.
I hope this helps.