My Real Estate Agent forced me (by intimidation)to sign a property contract higher than I stated/felt comfortable. Is this duress?

What was the intimidation?  If  he/she held a gun to your head to force you to sign, yes.  If he/she suggested that you should sign because you'd never get a better deal and you would lose money if you waited, no.  Wiothout knowing a lot more details, your question really can't be answered, and, even with all of the details, there may be no sure answer.