Sellers deal with anxiety, especially if they are also buying a home and depending upon the sale and closing of their existing home.
In addition, Sellers may have to deal as well with Buyers' anxiety. For example, you may have reached an agreement with the Buyers and signed the contract for the sale of your home. After the contract was ratified, you notice that the Buyers begin to behave strangely, getting somewhat agitated and making additional (sometimes unreasonable) demands, like asking you to include your new washer and dryer (that did not convey), or may start questioning the structural integrity of your home.
It is important to remember that people (especially first-home buyers) experience a high level of stress when they are buying a house. After all, it is the single largest investment most people make in their lifetime! Your Buyers may be suffering from "Buyers Remorse"-- a common feeling that makes them think they have paid too much for the house, or that the house is going to fall down as soon as they assume ownership.
Don't take it personally if your Buyers begin going through the "home-buying jitters". Be patient, and allow the REALTORS to do whatever "hand-holding" is necessary to get the Buyers reassured and happily settled in your home.