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 hunger and ate like half a pizza, then snacks and I felt way too full 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