You did nothing wrong. Short answer: you cannot be found guilty of infringing a TM that didn't exist at the time (and didn't know about). Unless the other party can demonstrate otherwise.
However, this move could neuter your domain name.
As said above, don't park your domain, be careful from now on.
Assuming you've been sitting on the name without developing it, then you accrued no rights whatsoever. Rights are derived from active usage.
If you are going to use it, make sure usage will not conflict with the newly-filed TM.
Can you be sued or UDRPed ? Yes, anybody can sue anybody over anything, especially in America. That is very unlikely though, because you need valid arguments to prevail. If you are lucky, the TM holder will approach you to buy the domain but no guarantee. He doesn't have the right to steal from you but he might be the last buyer you'll ever get for that domain.
Disclaimer: IANAL