I am happy for you, in that you have the courage to address this issue for your healing.
I feel it can take a lot of spunk to walk into OA, not knowing what might come next.

I tend to think drinking, doing narcotics, overeating, etc., is driven by the need to avoid dealing otherwise with feelings.
We might choose a behavior which helps us to be "numb to" or to "stuff"our feelings.

Over time, we then become addicted to the behavior (to the immediate relief the behavior brings).
In the meantime, we are doing damage to our bodies as a by-product of the addiction.

Is it our intent to harm our bodies? Possibly. We may or may not be conscious of the fact that we might be harming our bodies.
In my case, when overeating, I feel my more immediate intention/goal is to find relief for negative feelings.
I am not always immediately aware/conscious of the eventual impact upon my body.

I agree with ~Christina about self-harming behaviors, in turn, feeding more self-harming behaviors.

It's a blessing to have you around, J! You bring a lot of sunshine to the forum!