The interests of people who are lesbian, gay, bisexual, transsexual or intersexual are represented by organisations, for example the Organisation for Lesbian and Gay people https://www.lsvd.de/
Please visit http://www.netzwerk-lsbttiq.net/refugees/refugee-info
for additional information, also concerning refugees in specific.
If Your child is treated badly because of his or her sexual orientation, You can find support at http://www.vlsp.de/