You can get help from the youth welfare offices and health offices.
An overview of counseling centers in Berlin can be found here: https://www.berlin.de/familie/de/informationen/beratung-fuer-eltern-behinderter-kinder-146
Further information can be found on the website of the Federal Government's Disability Commissioner www.behindertenbeauftragte.de/DE/LS/Themen/KinderJugendlicheFamilien/Fruehfoerderung/Fruehfoerderung_node
Family Advisor: www.familienratgeber.de