Your house probably is not overpriced.
As Kenneth says: "If you are having showings the market knows your house is for sale and sees enough on line (photos, text, descriptions) to tour your home." That also means the market knows your price, and considers your price in line with what you're offering.
If your house WERE overpriced, then you wouldn't be getting showings. Potential buyers would be doing the research, consider your home overpriced, and would skip over yours to others. (Really: Why would someone spend valuable time coming to your home 2-3 times, knowing up front that it's overpriced. They wouldn't.)
So, they're seeing your home online. Other agents are putting your home on a list that potential buyers can consider. The buyers think your home--based on what they see online and in the printouts--is a reasonable possibility. The buyer's agents apparently consider the property a reasonable value--at least within the ballpark. Then then come and don't make an offer.
Something's going on. As Kenneth suggests, maybe your home needs staging. Maybe it lacks curb appeal. Maybe there are some funky odors that you've gotten used to that are bothering potential buyers. Maybe the room layouts and traffic flow are awkward. Or maybe it isn't your home at all. Maybe it's a neighbor's home that's discouraging your potential buyers.
You need to get feedback, as David suggests. Also, there needs to be a consistent follow-up with people who've viewed your home.
And, frankly, some buyers are just flaky. True story: I sold a manufactured home a few months ago. It was a great value, and it offered owner financing. It was marketed, in part, to potential buyers with not-so-great credit. Let me tell you: There's a reason why a lot of people don't have good credit. Many lack good judgment. There was the one individual who completed the contract, put some money down, applied to live in the community, and just never showed up for closing. There was a young couple who were going to buy but had to break a lease. They put down a down payment. They'd read the lease as requiring a 2-month penalty. They'd read wrong: It was essentially a 4-month penalty. Then there was the 33-year-old man with such poor credit that his retired parents in Florida co-signed for him. That allowed him to pass the credit check, but not the background check. Then there was the woman who absolutely loved the place...absolutely, absolutely, absolutely. (And it was ideal for her.) When I finally reached her a few weeks later, it turned out that her husband objected to the (relatively short) commute. You want me to go on with a few other examples? I thought not.
But the point is: check to see how your home is being marketed, and to whom. It's possible that part of the problem lies there.
So, have a talk with your Realtor. Have him/her run another CMA, just to make sure the price is OK. And of course adjust it if necessary. But with "quite a bit of showings," I doubt that's the real problem. Follow up with agents who show the property. Examine the property as if you were a potential buyer; look for weaknesses, especially those that may not show up online or in printouts.
Hope that helps.