You should talk to an accountant or CPA about this.
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.
I agree this is a tax issue, and may need to be resolved with an accountant. However, I have some concerns about the "false" SSN. If it was a SSN that has been issued to another person, there could be identity theft circumstances involved. If you applied for DACA with the assistance of an immigration attorney, you should discuss implications of using the false SSN with him/her. If not, then just appreciate that the SSN you previously used--the "false" SSN--may have actually been assigned to and belonged to someone else, and your use of that SSN could have consequences for the "true holder" of that SSN.
The person who posted this question, as well as anyone else who reads this response, should understand that the response is not, and should not be understood as, legal advice. Rather, it is legal information, based on the abbreviated facts presented. Immigration law is very complex, unfortunately, and immigration status adjudications are highly fact-dependent. The reader should retain an experienced immigration lawyer to analyze the facts specific to his/her particular situation to obtain “legal advice”; which this is not. Any answers offered on Avvo are of a general nature and informational only, and are not meant to create an attorney-client relationship.
I suggest that you contact a tax preparer that may be familiar with your situation. While there are many tax preparers this time of the year, I encourage you to find one that has a focus on undocumented clients as a specialty area. I have worked with such a business before with my clients and they were happy with the results.
The answer provided is general advice and does not constitute the establishment of an attorney-client relationship. Potential clients may contact me directly for actual legal advice based on their specific facts and needs.