I hope you are using a Realtor to represent you in this short sale as your buyer's agent. If you do have a Realtor, he/she should be in constant communication with the listing agent to understand what is happening with the seller's banks and when to expect each event to happen.
Having the first lender's approval is a very positive sign, but no deal is for sure until you get all lien holders' acceptance. Some second lien holders are not willing to accept minimal payoffs (usually less than $5,000 regardless of what is owed them) and can be impediments to getting a short sale approved. Some second lien holders will only grant a lien release and not a full forgiveness of debt which may cause a seller to back out of the contract because they can not obtain the debt relief they are seeking (a lien release allows the property to be sold but does not forgive the sellers of their debt and they must sign a promissory note to pay the debt in full in the future).
As noted below I would not give up your apartment without knowing 100% that your deal will close by the time your lease is up. You should do everything possible to negotiate a month to month extension of your lease to ensure you have a place to live (if the deal falls apart you may be months away from finding another home to move into).
If you are not being represented by a Realtor as a buyers agent then you are pretty much at the mercy of everyone else in the process.
Good luck, and I hope you close by the end of the month without difficulty.
Prudential Network Realty
3535 Highway 17, Suite 10
Fleming Island, FL 32003
I would advise you not to relinquish your lease prior actually receiving the keys in your hand. Short sale are tricky due to the fact that timelines are generally longer than a standard sale or even bank repo. I have seen short sale closing take anywhere from 3 months to 1 year.
Keller Williams Consultants Realty