Name and birth certificate issues

[Anarche]

I have a somewhat unique situation. I am currently applying for an employment-based GC in EB-1C and have to provide the usual info (birth certificates, etc). My situation is that I have my name as AAA BBB CCC. I was actually the biological child of my parents BBB but was brought up from birth by my uncle and aunt CCC. This was not a legal adoption and both my foster parents are deceased. My birth certificate has a blank name and my biological parents' names. My passport has my foster parents names and my name as AAA BBB CCC.

When sharing this with the attorney, he has advised to view all the documents that show the process and to take a formal legal name change to whatever (AAA BBB CCC or AAA CCC BBB or whatever) I want to use and to attach all the evidence, affidavits, etc. I am very concerned and would like advice from the experienced folks.

PLease excuse my confusing post, I will be glad to provide more details clearly.