First of all, stop beating yourself up! Stop it RIGHT NOW!!!!! You have come to you senses, you are trying to get back on track, and now you back here and asking for help before the situation gets even more out of hand. Pat yourself on the back for that!
Secondly, remember that you can start... today.... all over again. I don't know whether or not the second time will be 'harder' fo you, but remember that you have been off Atkins for only one month... many people here are on their second or third time after being off the diet for a year or more. Some of them are losing a bit more slowly, but you know what? For the most part, they are all still losing. The sooner you start back into the game, the easier it will be to stay, I think. And remember that we are on a spectrum, and there are some people here who would KILL to be at your weight right now. Most likely you have been feeling slightly guilty, but tere is absolutely no reason to feel embarrassed. Now, giving up entirely and heading back to the gym at 200 lbs. instead of 160.... THAT would be embarrassing. You might even consider exercising at a different gym or joining a class for awhile, and the people at YOUR gym will never even need to know that you slipped up. Atkins is a plan FOR LIFE, and you know that you can do this again. You have done it before, and there are lots of people around you to give you support.

And, on a more personal note .... Have you even considered that you came and asked this question on HALLOWEEN... SAMHAIN.... the ancient celebration of the end of the yearly cycle, trimming away the unnecessary, and the beginning of brand, new things? Now, how does that grab you as a little piece of inspiration?