Weight Situation

I had a doctors appointment today and I found out that I've lost 6lbs.
(Was 145 last time)
Either way I'm perfectly happy.
No big deal right? 
My mom is freaking out on me, I don't know how to convince her that i didn't like starve myself or something to lose that weight.
She's making me eat super fatty things so I gain weight again and I don't think it's necessary, nor is it for her to freak out like that!