weight recovery & maintenance plans??

I have been extremely ill with anorexia in the past, but nowadays I try to eat as 'normally as possible', however recent changes in my lifestyle have caused my weight to plummet and I am starting to feel really ill again. I am constantly exhausted and can't concentrate on anything, but I find it really difficult to come up with a truly effective meal plan that would get me up to a healthy weight that I can stick to, mainly because my appetite is so small.
I am 5"6 and weigh about 104lb. My ideal weight would be at least 126lb (probably a bit more).
I really need some advice as I have lost about 9lb in 2 months without meaning to & I'm going to uni in September!! At this rate I won't be able to cope :(
Thanks!