There needs to be more to this than what you have provided. The maximum that immigration can hold someone is 6 months 'if' they cannot deport him to his native country. If they refuse to let him go under an order of supervision than you can file a federal court case called a Writ of Habeas to have the federal judge review whether its reasonable to keep him locked up. There is more to it than you have described. He must have either a serious criminal conviction doesn't he? You need to obtain a second opinion and consult competent counsel and provide all the exact details to be able to get an answer.
I think you're missing a very important portion of the facts in your submission. Most cases with marriages to U.S. citizens resolve fairly quickly unless there is some criminal conduct that is causing the detention. I highly recommend seeking a second opinion. But first, talk with the lawyer you've spent time and money with. Ensure you understand the process first and then if you're still not satisfied then get a second opinion.
Get a 2nd opinion from an attorney.
It is possible that there isn't anything that your current lawyer can do.
PROFESSOR OF IMMIGRATION LAW for over 10 years -- This blog posting is offered for informational purposes only. It does not constitute an attorney-client relationship. Also, keep in mind that this is an INTERNET BLOG. You should not rely on anything you read here to make decisions which impact on your life. Meet with an attorney, via Skype, or in person, to obtain competent personal and professional guidance.