Panicking a little...

Dani ✨★★★ • 29. LPC, NCC, LMSW. Liberal. Married. Momma to my sweet Xochitl and Zahia. From Hawaii, living in Alaska.
So I'm 6wks today and went to my family practitioner for my first appointment this morning. She referred me to an OB (who I see March 7th) confirmed my pregnancy with another urine test, and answered a ton of questions for my husband and I. 
I'm worried though because when I asked her how much I should be eating, she told me my current calorie goal was healthy, but that I didn't need to gain any weight during my pregnancy. As long as I ate well and was active (which I am and I do) it would be fine and advisable that I just maintain my current weight. 
I'm panicking a little. And by a little I mean a lot. I moved here (North Dakota) from my home in Hawaii two years ago and have gained about 40lbs since moving here (severe lifestyle changes, depression, winter for the first time....its been REAL rough). I know I gain weight easily and struggle to lose it, so I'm SUPER paranoid about weight gain now. I don't know how to make sure I don't gain ANY during my pregnancy?!?!?
I'm overweight, I've always been fat, but I'm not obese by any means and I am just so confused...anyone have similar experiences?