In the French-speaking community you can contact the psycho-médicaux-sociaux (PMS) centre of your child’s school . www.enseignement.be/index.php?page=24633&navi=2325
In Flanders, you can contact the CLB through your child’s school.
http://www.onderwijs.vlaanderen.be/centrum-voor-leerlingenbegeleiding-clb
In addition, as Belgium has an active gay and lesbian community there are several associations and social groups you can contact. For instance:
Alliage - Gay and Lesbian Association Belgium. This association is supported and partly funded by various official bodies. It supports gays and lesbians faced with discrimination and also offers counselling services. Although based in Liège, it provides information and links to hundreds of groups and associations throughout Belgium. http://www.alliage.be/accueil.html
Arc-en-Ciel Wallonie - Fédération wallonne des associations LGBT https://www.arcenciel-wallonie.be/
Holebifederatie is a gay and lesbian association for the Flemish speaking community in Belgium. https://cavaria.be
For other associations: http://www.lgbt-lux.be/associations/