<p>Didn’t the OP says he is not in contact with his adoptive parents at all?</p>
<p>“Since my (added: birth not adoptive?) parents are not in the working age anymore, I’ve been working part-time jobs and all to pay off myself.”</p>
<p>Your adoptive parents can’t kick you out of the house and not support you, and still claim you as a dependent. That’s when you should declare yourself independent with the help of a lawyer.</p>
<p>Family Services in your county or your college’s county might have some ideas.</p>