This could be translated in two ways:
"If they hadn't touched me, I would be quiet."
OR
"If only they hadn't touched me, I would be quiet!!!"
I'm not totally sure (without more context) about which is the better translation. For Russians, note that the difference between "if XYZ had happened" and "if only XYZ had happened" is that "only" transforms a "neutral" contrary-to-fact statement into a strongly emotional wish. In other words, the difference is not simply stylistic in English. But as far as I know, "если бы" can have both meanings.