Good evening. My guess is; for this to be successful and set the tone for lifelong help you are going to need professional assistance because of the existing eating disorders.

Your BMI is a good reason; but I believe you will benefit more in the long run focusing on the bulimia/anorexia first and the healthy body will be part of the outcome.

Hopefully that makes sense. These forums are generally "healthy" I don't see people advocating unhealthy weight loss measures, although you can tell there is a lot of personal food demons people are dealing with. However you will notice things like those who will lose faster than others or those with lower final goals than other...especially if they are at your specific height.

I am concerned that those aspects of the boards might become unhealthy triggers for you.

Best of luck. I have got much inspiration, ideas, and compassion here.