Another way to say it that's quite common in Spanish is "Ten paciencia."

"sé paciente"

Also just to note if you enter a word into wordreference.com and tap on the => next to the verb it will go to the conjugation. You can also select conjugation in the drop down menu. In this case you are looking for the imperative form.

Gracias, me da confusion porque es la mismo del forma yo de saber.

La forma correcta es "Sé paciente", ya que corresponde al verbo "Ser", y en ese caso siempre lleva acento