Calorie/ Metabolism Slump

Hello all,

Last year, I went on a pretty extreme fitness regime. I was 61kg, I am 165 cm's tall and though my BMI is Healthy I am neat the upper range and if I went down to say 56-57, would still be in that.

I ate 3 meals of 300 calories a day, and I walked each day for half an hour and naturally, lost 7 kg in 3 months. I really did look fantastic, I have always eaten good food and even though the meals were tiny, they were comprised of lean protein, vegetables and whole grain where possible (I don't eat dairy, I think its bad for you). Everything was great, then I met my boyfriend, and slowly forgot about my diet, and needless to say, it has been roughly 1.5 years since I was that weight and I think maybe 5-6 months ago I went back to the same 61kg I still eat healthily, just obviously more food, I stopped excercising and now I am more wobbly than last time, and also, I find it almost IMPOSSIBLE to lose weight. I have started by going back to pilates and Bikram (I do bikram once a week and pilates 2 times a week) and will up that each week, I eat 1200 calories a day and WAIT! I Know what you will say (that's very low, it was all very low) and I am aware of this. Thing is, I actually had this body test done 6 months ago, she said I had an abnormally slow metabolism. My Body fat is 30.5% though I have no fat around my organs almost at all which is good and I think I have a small frame because I can touch (if not overlap) all my fingers around my wrist.. My arms and legs are slim but my stomach/chest is my problem... I looked so good at 56kg and in proportion.. I feel like I may not lose weight eating 1200 cal, orif I do it will be incredibly slow and I figure I have F#*!ed up my metabolism... I admit there have been times where I have forgotten to eat for half a day, then eaten a huge meal before bed for example... Though usually I do eat/snack enough. Do you think I should start trying to eat more calories per day? I find it hard to imagine how I can up my calorie intake to any more than this... or forcing in a nother meal.. does anyone have any tips? I want to lose but worry I won't...

Thanks