You are not legally entitled to keep money that was paid to you by mistake. It sounds as if you knew that you were not entitled to the money but spent it anyway...and that won't reflect well if the matter proceeds. On the other hand, in this economic and political environment it is unlikely that the government is interested in putting you out on the street. I recommend that you try to work out a repayment plan.
There are a lot of variables here. First of all and most importantly, why were you overpaid? There are two ways to appeal. Filing a reconsideration says it is incorrect that there is an overpayment. More commonly, people file a waiver, which says ok, there is an overpayment, but it is not my fault (I either didn't know about some event or I reported it, but it was not acted on by Social Security) and I can not afford to repay it. If this is what you filed, and you have appealed it, you will have a face to face meeting, called a personal conference, to explain why the overpayment is not your fault. An example might be that you had mailed (and have proof of this) your changes in workers compensation, and Social Security did not process them timely. I assume the "without fault" is your problem, not your ability to repay. Now if this personal conference results in a denial , you may file a request for hearing and then you can explain the situation to an Administrative Law Judge.
You also could work out a repayment plan or an offer to repay a big chunk (all at once), but not all of it. If you are still getting checks, you may ask for partial withholding. The government will not throw you out into the street, but they also do not forget an overpayment. and will get it eventually, so best to take action now.
You are correct to Appeal, SSA is wrong much of the time. While you do not go into details about why there is an overpayment, I have seen plenty of cases where the alleged overpayment amount is incorrect, there was improper notice by SSA, or no overpayment exists at all. Try calling NOSSCR (National Organization of Social Security Claimants’ Representatives) for an attorney referal at 800-431-2804.