Try saving your wallet.dat file on your desktop or wherever you want.
Then, delete all the content from the Pesetacoin folder on Roaming (Windows) or on Application Support (Mac) > Reopen the Pesetacoin-QT > Go to the Roaming folder and create the new .conf file with that working nodes:
addnode=188.138.16.83
Then, copy your previous wallet.dat too, confirm and reopen your wallet. Let's see what happens
It should be working... haha