i have the exact same situation. i think i might write my mom an essay since she is a teacher and if i do something like that she might accually read it. i think you might just ahve to break your mom in since you said you are the first son to smoke weed. one of my friend's brothers was a first child and i remember being there when she found his bong and a whole bunch of weed, and always had problems with him, then there was another brother that did it, then another, and thne finaly my friend. now her mom smokes joints with her kids and whne the first kid came back (he moved far away) he was like "wtf?!". true story.

just do something you mom would give you respect for and let her know you dont intend on quiting