Lose weight when you're ready to and if you want to...I find I can keep my mental health by eating what I want with a calorie limit. I don't force myself to exercise or eat healthy. I eat tv dinner mostly and all that jazz. It's not the healthiest, but I keep my mental health. I just count calories and stay under my limit, which is 1500. I've lost 20 pounds pretty quickly...and it doesn't seem like a diet, just being kinda...well, caring about what I'm doing.
I have a pretty good mental health despite disordered thoughts every now and then, but they get less and less...I don't worry about other people's thoughts on the subject, only my own. My own opinion seems good enough to me.