回複：pingponglover - i know my question was stupid

"the way i handled tax was to pay extra tax on W-2, so almost all of my salary on w-2 went for income tax"

This is just not plausible, unless you print the W2 youself (W2 not from your employer) all the "extra tax on W-2" will be refunded to you by IRS. The contract and the checks with the company will be the proof of bona fide self-employment.