Your attorney is incorrect. You can file for adjustment now. USCIS has a concurrent (and exclusive) jurisdiction under the 2006 regulations to adjudicate adjustment of status for arriving aliens. In many court cases we have succeeded to obtain status for our clients first and terminate the proceedings later. You should consider immediately switching attorneys and find a competent and experienced Immigration Counsel.
Kindly be advised that the answer above is only general in nature cannot be construed as legal advice, given that not enough facts are known. It is your responsibility to retain a lawyer to analyze the facts specific to your particular situation in order to give you specific advice. Specific answers will require cognizance of all pertinent facts about your case. Any answers offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship.