I had the same problem. You could check with your OSO and see if you can get PTAD - working in the OSO office while pulling pay. I wasnt able to do that because I am air and going to IFS on the 15th, just like KizerSosay. My OSO said I couldnt get PTAD because I will get paid enough for doing nothing while Im in IFS. Im assuming you are air (being on this website and all) but if you are not its something to look into.
I got a full time job to pay the bills and told em when I found out I was leaving. Some employers are cool with you being a Marine and all, but others wont care. If you need money, which Im sure you will due to your family sit. and all, you might have to do what you have to do and just ... well ... not mention the whole leaving in a few months part. Best of luck.
Semper Fi