So I used to be super into health and wellness pre-trauma, and since physical and PTSD issues prevented me from the gym and changed my whole life, I've gained some weight and have not been able to workout the same since. I'm working on it, but, like you, I was using the number of the scale and what I put in my mouth as a form of control. Do not be shy in seeing a dietician. It's super super helpful to even just talk about it with someone. We generally know most of our thoughts are irrational, and if we are going to do some form of restriction, at least being engaged with a dietician will help us do it appropriately, and or keep our harms down to a lesser degree.
Even when pre-PTSD when I was super healthy I would see a dietician. To me, it's like going for regular check-ups at the doctor or dentist office. The resources are available? USE THEM!!!