I'm going to make some assumptions here; forgive me if they don't apply in your case.
First, let's say that you did the research to find a musical instrument that would suit your music-making needs. You found it. Let's say also that having found it, you began anticipating owning it, and after making the decision to buy it, you became excited. Excitement is natural.
But let's say that you didn't buy it for the excitement. Let's instead speculate that you bought it for the reasons you originally researched it.
If so, the excitement part has absolutely nothing to do with your interest in the instrument. It's a by-product. And as such, it's not really logical to pursue having more by-product. The by-product is where people get GAS and in truth, GAS does nothing for your music. Really, GAS is counterproductive, because you focus on acquiring instead of the reason you bought an instrument in the first place.
Unless, of course, the reason you bought the instrument is to have an instrument collection. That's a different thing, I suppose.
We all know folks who buy for the sake of the thrill. But the thrill wears off very quickly, as we have seen with folks buying and selling constantly. My feeling is that if one has to churn new stuff all the time, something irrational is taking place. So think about why you acquired this instrument, and then take a deep breath and just enjoy it for what it is.
You probably don't truly need to have every shiny object out there that you find appealing. We all joke about GAS, but for the most part, GAS is a symptom of just needing a thrill and a little excitement that you're not getting elsewhere in life.