Assuming there are no other issues and your marriage is a good faith marriage, you can obtain your green card through your US citzen wife. Please consut with a lawyer.
Madrid Crost Law Group - (888) 466-4478; e-mail: firstname.lastname@example.org; skype: usvisalaw 10 S. La Salle Street, Suite 3320, Chicago, IL 60603 Please consult with a licensed immigration professional to provide you with a thorough legal advice. This response is not a substitute for specific legal advice and it should not be construed to create an attorney-client relationship. Please help stop notario fraud. Please visit and share this site: www.stopnotariofraud.org.
Because you entered legally, you might qualify to adjust your status here, without having to leave the country first. Like my colleague said, this is assuming there are no other issues in your case. It's important to consult with an immigration lawyer before doing anything.
The information offered is general in nature and not meant to be relied upon as legal advice. No client-attorney relationship is created through this information. Please consult an attorney prior to making legal decisions.
Your girlfriend can sponsor you IF you get married. The overstay will be no problem when adjusting through an immediate relative - spouse.
If you are married to a US citizen and meet all of the other requirements you should be ok. Make sure you work with an attorney, as these applications are extremely complex. My firm handles such cases in NY.
Law Offices of Nicklaus Misiti
212 537 4407
Legal disclaimer: The statement above is general in nature, as not all the facts are known. You should retain an attorney to review all the facts specific to your case in order to receive advise specific to your case. The statement above does not create an attorney/client relationship.