06/27/1971 Was adopted in Frankfurt Germany

I was born and adopted in Frankfurt Germany. I am looking for by birth parents. I am not looking to hurt there new family I would just like to meet them and say thank you for letting me have a wonderful life my adopted family has been such a blessing in my life that nothing could replace them. If you have any idea on how I can go about finding my birth parents please get in contact with me. I am a single parent so I dont have any money to spend on PI and things like that. So any help will be appreciated. Thank you