

Having an Inner Critic is normal, but you seem to have fed it, until you believe it is true. It’s not. I hope your therapy does help.
You know what’s funny? I have the body dysmorphia, like still cannot see myself as having a good body, and usually mirror or photo just confirms this. But one time my husband took a picture when I was just in underwear, so nearly naked, and I looked so good, it’s like somehow he captured how he sees me. And we have one flattering mirror in the house, I thought it was like a fun house slimming mirror, asked my kids and they were like, no, that is how you look.
So if you have someone you can trust to bounce things off, that can really help, occasionally others can see past your insecurities and give a clearer view.
Well I am on the other side of this, I feel so fat even though objectively not overweight at all (BMI of 22, and pretty lean) because I was underweight a long time so in a relative sense I feel fat. I also feel better than I ever did when underweight, physically, and my bone mass is a little better (which is supposed to be impossible to achieve at my age) and that pisses me off, I want my healthiest weight to be the size I like better.
I don’t think it’s good for you to enable them in losing weight, no. Unless you are 100% sure they are not falling into disordered eating. It’s their body, you can’t control that but it’s fine not to support or help them with it.
As someone prone to eating disorders - the suggestion to work out is solid. I find it much better to focus on athletic goals and just let form follow function. It’s good to be able to feel good about what my body can do.