Michelle, your story is very similar to my own... my highest weight was 180 and I lost about 60 pounds and hit goal 2 years ago. Since then, I put about 25 or 30 back on, and I got back on the diet at 150. Now I'm working to get back to that goal (or even a little above where I was before, which was very skinny), and I am so excited to fit into my skinny summer clothes!!
I am doing Weight Watchers. I have tried many diets (Atkins and grey sheet were probably the two most successful next to WW), but this diet fits my lifestyle and has taught me invaluable lessons on how to be healthy, even when I'm not trying to lose weight. I lost the 60 pounds in a few years with WW, and I will never try another diet (although I do drink Slimfast as part of WW, so you could say I do the Slimfast diet too
)As for battling cravings at the office, what I have found most helpful: let's say your coworker brings in a box of pizza for everyone (this happened to me yesterday doing inventory). I was so tempted to eat it because it was THERE, but then I thought, "if I want pizza, I can always buy a slice later today. I'll wait a few hours and see if I still REALLY want it." And of course since it was just a fleeting craving and not true hunger, I didn't want a slice later. Try telling yourself to wait for a few hours, and usually the craving will pass. Also try to pack healthy lunches/snacks so that you don't get so starving you have to eat junk.
Hope that helps! Good luck!!