Nope, not in jail. I went down to immigration today and "confessed". It was a breeze. I just told them I forgot to renew it. They had me write a short letter explaining my situation. I gave them a copy of my e-ticket, (which I did voluntarily, they never really asked for it). The only problem was the long wait, which I expected anyway. They changed it to a visitor visa (which I requested) and extended it until the day I leave.
Thanks for all your help and comments.