Thank you bzylzy and pemberley!
Art therapy is quite expensive and we already spend a lot of money in helping DS. The first time I posted on this forum was exactely on rising my DS self-esteem. I read this post several times. Tried a lot of things, but it is so hard when you and DW have a job, have to get everything in order (meal, house, washing,..). The time which remains is mainly dedicated to his school challenges ...Fortunately, it helps him keeping in touch with what happens at school. SO he is not trully broken ... But at home, he is still a kind of storm, very hard to contain.