As the others noted, there's no way to "roll over" a loss from one property to another.
It's a tough situation. I know several people who bought in Gainesville while the market was hot. There are some nice properties out there. But the commute was always brutal. And now with gas at $4.25, it's pretty expensive, too.
Without checking the comps, your estimate of the potential rent seems about right, as does your estimate of the decline in values. You should pin down those numbers with a Realtor.
You might be able to increase your monthly rental somewhat (a few hundred dollars) by offering the property as a lease-option.
Meanwhile, it sounds as if the New Hampshire home is a real drain. Aggressively try to do something with that. Get someone in there paying something. Consider a lease-option for that property, too. If, for instance, you're paying $825 for an empty house in New Hampshire, even if you just got $600 a month, that's $600 more than you're getting now. And if you could bump up your income from the Gainesville property by $250 a month, that's a total of $850 more than you're receiving now. And that would narrow your projected $1,800 a month negative cash flow on the Gainesville property significantly.
Then, you might think about renting rather than buying in Lexington Park. I'm not very familiar with the area, but your goal is to trim your expenses to the bone and to increase your income. Trim those expenses by renting for awhile. (Hey, maybe even consider finding a property available as a lease-option in Lexington Park. It should cost you barely anything more than straight rent.)
Check with a good CPA on the tax implications involved. And there may be ways to help address your situation that a CPA could help with.
Hope that helps.