I failed last night, too. But I didn't fail completely, I just fell down. Today, I'll get back up again. So, I hope, will you.
I'm no expert, but I've learned a few things in my 20+ years of disordered eating. One of those things is that beating myself up after a binge, no matter how thorough and vicious the mental beating, never prevents the next one.
I could be wrong, but I think I'll always have the occasional fall. But I don't believe I'll fall back into full blown binge eating episodes, mostly because I refuse to let the self-hatred take over.
It's easier said than done, but try not to be so hard on yourself. Talk to yourself the same way you would talk to a friend who is living with disordered eating. You deserve the same compassion.