How about:
"Volo pacem, officio paro bellum." I want peace, out of duty I prepare for war.
The verbage here is taken from the saying "vis pacem, para bellum." If you want peace, prepare for war."
Your phrase literally means "I make towards peace, dutiful I prepare for war."
Officiosus feels clunky too me, and its a bit too direct -- it sounds standoffish. It would be easier to use the ablative form of officium, officio, which I think gives a better sense of obligation to one's duty without obviously glorifying oneself. Adfecto feels too verbose and its meaning shifted very early on in Latin to a negative connotation. Not only that but its meaning changed substantially. I don't like gero (certainly not in the present), because it effectively says that you are presently waging war. It seems to me that war is your last resort (although I might be misreading your intentions), but if I am correct then you want a word saying that you're prepared to fight, and not that you are fighting.