With analog I received 2,4,5,7,9,11, and 13 out of NYC, I'm 20 miles away as the crow flies.
With digital I can only get 7. 11, and 13.(VHF)
I understand that 11, 7, and 13 are VHF and 2,4,5,9 are UHF.

Will a smart antenna fix this ?
I have a roof antenna that has UHF and VHF, and I told it's pointed in the right direction.

HELP !

Have you checked all the connections at the antennas; if the former low V's are now UHF channels then sounds like something has gone wrong with the UHF antenna or connections or how they are joined. I would check for corrosion or anything having to do with the coax or line from the antennas to the inside.

With analog I received 2,4,5,7,9,11, and 13 out of NYC, I'm 20 miles away as the crow flies.
With digital I can only get 7. 11, and 13.(VHF)
I understand that 11, 7, and 13 are VHF and 2,4,5,9 are UHF.

Will a smart antenna fix this ?
I have a roof antenna that has UHF and VHF, and I told it's pointed in the right direction.

HELP !

Sounds more like you've lost all your UHF channels and are getting only the ones broadcasting on high-VHF.

Sounds mire like you've got a VHF-only antenna or that you've got something inline that is filtering out the UHF. This could also be due to a failure of the receiver.

A "smart antenna" is the last thing you need (since you don't need one).

Since you only got VHF before, it sounds like your antenna is not really VHF/UHF or there's a problem like bozey mentioned.

If considering replacing your antenna, skip the "smart" antenna or gimmicky looking antennas, in favor of a good VHF/UHF combo (http://www.solidsignal.com/prod_display.asp?prod=HD7694P).