I’m of the opinion that Stark has a lot of scripting related to the element of Air, and when you overexpose this element tends to get out of balance.
Air is also the intellect, too much causes insomnia or overthinking.
If you reduce loops it might help to balance that element—this worked for me on the store title.
Otherwise, I’d give Deep Sleep, and Lion IV a chance the latter is great for grounding. With lots of Air you need Fire to transmute it.
That being said, you can just lower your exposure and I’m sure the insomnia will start to decrease. Just find your balance?
When I had Stark in a Custom with Chosen, Deep Sleep and Lion Iv, I no longer had the insomnia problem, probably since it was more diffused and also because it had more a balance in the elements.