You're so close...just keep going a little more.The suffix -er, when added to a verb, references a person or thing that does an action indicated by the root verb
I don't know what else to tell ya, no serious etymological research supports what you are saying. You can choose to believe the truth or not, its up to you:

-ment - Etymology & Meaning of the Suffix
From Latin origin, this common suffix forms nouns from verbs, indicating the result, means, or instrument of the action, evolving through Vulgar Latin and Old Fre...