Duplicate your background layer. Right click and "convert to a smart object". Then go to filters ->Other->High Pass. Adjust the radius until you can just barely start to see some of the picture ( probably like 2% for a normal pic, but if you need a lot more, jump it up to maybe like 5% and see how it looks. ) and then click ok. Then go to that layer and change it to "Overlay" You can always go back and double click on the HIGH PASS listed under that layer and re-adjust as needed.
As others said, this isn't going to fix the problem. Its very easy to oversharpen and introduce a lot of noise. Just because its no longer as blurry doesn't mean its better, you could in fact make it just as worse in another area. If its got definitive shapes in the pic, you could always go the other way and intentionally blur it to give a sort of dreamlike, ambiguous feel to the pic. Maybe not what you want, but atleast the pic wouldn't be a total waste.