I was diagnosed with Binge Eating Disorder almost 4 years ago, and I was just sleeved on June 4th.
Everyone is different, but I wouldn't have been ready or prepared to take on the surgery before this point. I think the important thing is to talk to your eating disorder therapist if you have one about whether they think it is the right time for you. Many will be supportive of your decision for WLS once you have been binge-free for a certain amount of time and have gone through the proper ED programs and are considered "in recovery."
Setting yourself up for success in the most important thing, even if that means taking some more time.