Even though you have changed your address, you account is still a UK registered account.
You won't be able to sort out your postage issues and there will be problems with VAT etc.
If you want to sell while you are in Italy, you could open a new account.
You will need a different email address to the one you use for your UK account and, I assume, an Italian registered bank account.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)