Since i cut out fizzy drinks and fast food from my diet,iv put on 6 pounds/3 kilos and unable to lose it.is this normal?

I am a huge chocolate lover (one bar everyday) so my chocolate intake did increase quite a lot when I first stopped all the junk-to one SLAB a day.I also started eating a lot more than usual which i figure was due to my fast food cravings,and due to a number of reasons stopped my only form of exercise-moderate paced walking once or twice a week. This lasted about 3 months and i put on 3 kilos (mainly a bloated stomach).I would just like to say before this i ate A LOT of junk food,chocolate and sodas and maintained my normal weight. Anyway, since the 16th of March,i went on a "diet"..still containing my daily bar of chocolate but very healthy in comparison to what I usually lived on. Also,for almost a month I have started doing stomach and arm exercises and walking for about 45 mins at a moderate pace. Up until now though,there has been NO weight loss. I have a history with eating disorders (starving myself) and find myself quickly slipping into old habits..I am constantly at loggerheads with my myself and eating-do i try eat normally and heathly with no results,or do I take the tried and tested starvation route,where i lost a lot of weight,and managed to maintain it,even though it was stupid. I know the obvious answer but it's not as easy in my mind,as i have once again become absolutely obsessed with my weight. This is obviously a shortened version of a much more complex story but I'm just looking for some advice,when or if I'll ever see the weight loss etc.

weight-55 kilos/121 pounds

height-159 cm/5"2'

I know I am in no way over weight but i AM unhappy,and desperately need to do things the healthy way before i go back into a full blown eating disorder.

Thanks so much for the help in advance.

edit: oops - at first i read your height as 5'9" and was going to lecture you.

given your history, i think it would be a good idea to stop worrying about your weight and concentrate on your health.  also, try to broaden your perspective.  i heard the other day about a new study that has found that people with anorexia are hard-wired to have rigid thought patterns and to focus on details rather than on the big picture (which is highly consistent with my own research, btw!).  you can change this, but you have to work at it.

in the big picture, the number on the scale is really, really unimportant.

I am your height and I would kill to weigh as much as you do. In fact, it is my goal weight... The number on the scale is really unimportant if you are healthy. I say keep the healthy route up until you start seeing results. I've been eating healthy and exercising everyday for two months and I'm not seeing a drop in weight... In fact, I'm not even fitting into my old clothes but does that make me stop? No, because I know that I am healthy. Starving yourself might get you the number you want to see, but you won't be healthy... And the important part is your health. I'm still hoping my body will wake up and start shedding kilos, but I'm not going to let that rule my life. You shouldn't let this rule yours, either. Just keep exercising, focus on toning up and you will feel tons better. I know that I do, even though I haven't lost weight, I have more definition to my arms and legs and even my stomach, and that helps.

I was a chocolate lover too..for years and the more sugar and salt the better. And of course it is in most fast foods..a lot of it.  ..2009 changed all that...I started a daily check on my Blood Pressure and pulse..by early Jan 09 I was heading for a heart attack.  

You might want to monitor your heart..you can bet a monitor at any drug store.  At least you will know if what your doing is right for your heart.  

Anorexic tendency is a serious problem..you can cause a lot problems for your thyroid and digestive system...usually resulting in Vitamin B deficiencies.

With your situation I organs...so I would strongly recommend you work with a qualified Doctor or health care professional.

nvm

Questions 
What is more important to you?  Losing weight or being healthy and having a good quality of life?
Are you willing to live this rest of your life with health problems or would you like to grow old and still be active in mind and body?
Are you eating enough calories and healthy foods to reach your long terms goals?
And out of curiosity, what kind of chocolate are you eating?  I love 85% dark chocolate, because I find that I can have one or two squares and be stated with it.