I'm not sure what you mean by "signed my rights over." If you mean you executed a consent to adoption, there is likely nothing you can do. Adoptions are intended to be permanent terminations of parental rights and for all legal purposes you are no longer the child's mother. If this was an adoption, you could consult an attorney to see if there is anything you can do, but absent very peculiar circumstances (which are not indicated in your question) there is nothing you can do to reverse the adoption.
If you mean you entered into a guardianship, then that guardianship can be terminated if you can make appropriate showings. This would be a legal proceeding and a somewhat complex one. I would strongly suggest you seek the services of an attorney.
There are not enough facts here to try to give an answer. You need to consult a family law attorney ASAP. Bring all your papers with you.
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