You are doing the right things. That piece of wood was not a good hide. Your snake will like the ones that you made. We commonly use "flex watt" as an under the tank heating (uth) source here. While this may not be available to you, there is a product called "Ultratherm" which you should be able to locate and purchase in Europe. This is a heat pad that you tape to the bottom of your viv. I would buy the smallest one to put on a glass bottom.