Hi James, welcome back and well done for acknowledging the gain and deciding to do something about it. Like others have said above we all do it, I regained the 3 stone I lost on VLCD and am now in exactly the same position I was in 2 years ago. Sadly I can't do Atkins as all the years of yo-yoing have caused gallstones so I can't tolerate the fat but found a combi of VLCD + 100g protein and 200g veg and I'm back on the way down. I had a planned lunch on Saturday and knocked myself out of ketosis but only really for Sunday. You're so determined so I'm sure you can get yourself back into K prety quickly too.
Good luck, and please vent here and put down in words your feelings too. Afterall where else in the world could you find so many people who really do know what you're going through? People say they understand, but we've actually lived it!
On the point of other people's reaction to the gain I get in first and just say 'yeah, typical me eh?' then state honestly with a shrug of the shoulders that all I can do is lose it again. Generally people are kind enough to say that until I mentioned it that hadn't even noticed. Even if it's a lie it's generally the end of the conversation lol.