If you sold the property, then the deed should be recorded in the name of the buyer. You don't need to care about that. What you need to care about is that the mortgage was recorded in the same government office as the deed. The mortgage is what protects you against default by the party you sold to. And you need to care about the mortgage document giving you the right to foreclose on the mortgage if the party you sold to doesn't pay the taxes. If the document does not say that, then you stepping in and paying the taxes before the town can have a tax sale might only benefit the party that you sold to. Because if they are not in default on the mortgage, you may have no grounds to foreclose on them.
I suggest getting an attorney on this tomorrow.
Edit: Whoever gave this thumbs down is clueless. When you sell, you transfer the title subject to any mortgage you may have taken back. That mortgage gives you the right to foreclose and recover the title if the loan goes into default, and MAYBE if the taxes (and/or hazard insurance) are not paid. Any mortgage you get through a bank contains language addressing the requirement to keep taxes and insurance current and spells out what the bank may do if they are not. Banks will pay those taxes/insurance to protect their property rights and then they will foreclose.
Which is why any mortgage that you are holding needs to have something to that effect written into it. If it does not, again, then the party you sold to is not in default on the mortgage until they stop making the mortgage payments.
I dare anyone to, instead of giving a gutless anonymous thumbs down, to explain how and where I am wrong.
Now, if this was some sort of land contract, where the buyer doesn't get the property until all of the payments are made, then the deed would of course still be in your name. But it's not. Real estate professionals don't get involved in these land contract deals.
Again, you need to get a lawyer...immediately. One more day you wait is one day closer to the government holding a tax sale.