Hey Wooo,
I think (and I think you know) frequent small feedings are the answer. I would think it would be possible to keep LC snacks at the office. In many countries, a "bun break" or "elevenses" (cup of tea and snack in midmorning) is a normal part of the day, and also afternoon tea (at about five). You could schedule in these snacks to boost your intake without feeling overfull or sick.
As you know, starvation breeds starvation...for a while at least, the less we eat, the less we want to eat.
I have to wonder (having read some of your other threads and posts) how much your ED tendencies/history figure into this. I know that for myself, the process of losing weight is more "achievable" than maintaining...seems easier to pursue a goal than to try to stay in the same place. Also, self-denial becomes satisfying in itself; and it is hard to shake the deep-rooted "smaller is better" misconception. Does some part of you enjoy the increasing boniness, the attention, the "you are too thin!" and "you need to eat!" comments? That is the part that is working against you. Does your inner fat-girl enjoy hearing a certain amount of that kind of thing? (I speak from personal experience; when I was your age I went through this exact situation.)
Intellectually, you now want to maintain instead of lose; your unconscious may be working against you, though. You seem self-aware enough (again, I infer this from having read other posts from you) to confront and address this if it is true.
So my advice is: take your bun break (without the bun
) at 10.30-11ish AM and your tea break at 4 or 5 pm. Added to a reasonable breakfast, lunch and dinner you should be able to learn over time how to keep yourself within a 5-lb range of weight.
Of course, take my advice with a handful of salt bcs I am new at this maintenance-biz myself, and I personally think that this is the hardest stage of all: basically, it's the rest of your life. I am hoping that things which are initially regimented (and somewhat "forced" as you say) will become second-nature and habitual with time.
Good luck, Wooo
Lucy