I liked Barullos, where I sat on a balcony looking down on the plaza and cathedral. The service was excellent and the atmosphere pleasant, with candles on the tables. I ordered a house specialty, Discada Barullos. Staying in Catemaco means settling down to a quiet pace. Traffic is almost nonexistent, and you can easily walk from one end to the other of the tourist district.
Shops sell shell objects, leather purses, hats and so forth without pressure.
I too felt regret. Rent a car at the airport or take a bus to Catemaco from the terminal in central Veracruz. To visit Tres Zapotes, exit the Museo Tuxteco in Santiago Tuxtla. Turn right and walk to the first street. Turn right again.