I have turned several people here at work on to fitday.com. it takes a little work sometimes to have to add your custom foods, but it really keeps up with it.
to find out how many calories you need to maintain, take your body weight and multiply by 11. if i am not mistaken, it takes 11 calories to sustain each pound you have. then you need to subtract some calories from it to equal one pound a week. but if you excersize, you can deduct those calories from your diet too.
like, i weigh 179 so 179 x 11= 1969 calories to maintain. So i dropped my calories down to about 1400 a day. that's a deficent of 569 calories a day. over a week, i should have a deficent of 3983. so without excersize, i should be able to drop about a pound a week. not that it is really working out like that. but then again, the past two weeks, it has been working out for me, because i have been zig zagging my calories.
if you keep your calories the same every day, your body starts to rest. so you have to mix it up to keep your body guessing. today, i will get about 1000-1100 and tomorrow, i'll probably be back up around 1600.
but don't give up and don't starve yourself. You said you were anorexic before, well, i was too in highschool. and i remember, being dizzy when i stood up, i had short term memory losses, i was a size 3 but still have fat on my belly and thighs because i did not tone up those muscles. i lost those muscles from lack of protein. i was tired, i slept in class. it was not a good way to spend my senior year in school.
just relax and realize this is a lifestyle change and it won't come as quickly as we want it to, but it will come and we will be more healthy because of it.