I wanted to say that there is no much to do about it at this moment and that any changes might kill him also like reppoting, transporting etc. Unfortunately yesterday I took off few layers of the soil from the top to see if the soil is to much clayed, and I found not so many small white worms in it. And small white insects. As I found out the worms are result of over watering or bad soil. And when they have eaten all food in the soil they start to eat the roots.
The trunk is still alive, so I guess its dying slowly. There is only one expert for yamadori bonsai in Macedonia and I ll wait for his return in the town next week if he can save him.
However I would like to thank you for all your help and I ll be happy to inform you with any good news.
All the best