How to stop purging for good?

So I relapsed today. I was a week free from it and I had dinner today and I just felt this ravenous hunger and ate like half a pizza, then snacks, and just anything I could get my hands on. I felt way too full like I was gonna die. so I purged. I’m so ashamed of myself I really want to fully recover but it seems like I’ll never get away from b/ping. How do I stop with this urge that no matter what I try I can never stop it. I feel so defeated right now and tired