I have never liked having my picture taken, even at relatively 'thin' times in my life.
But when I got married ...I didn't have much choice.
Interesting, the photographer that we hired took some color and some black & white....and the black & white ones look pretty good. Much less harsh and more flattering to a 'full' figure. So you may want to try that.
Also, I read once that professional models practice their best 'angle'. I don't know about you, but I don't even like to look in the mirror let alone practice, but okay, I did it a bit, and now know that I look best if I look off to the distance, a bit to the left or right, and upwards...sounds odd maybe, but the harsh glare of a camera 'face on' makes ANYONE look awful...

So, good ahead, take your picture. My mom died when I was 18, and I have less than 10 pictures of her....and as I write this, I have tears in my eyes....so there's no need to say more is there...

Love to you all....