Help! Regarding Calorie Intake

Fluid actually doesn't impact weight loss imo (I drink for hydration). Weight fluctuates naturally for a host of reasons. You lost 7lbs in your first week, most of that will be water weight rather than fat loss and that is normal. The loss was always going to slow down. 2 weeks is not enough time to see progress. Keep doing what you're doing, trust the process and slowly but surely weight loss will happen. It takes time.

1200 might not be enough for you but eating more never aids weight loss unless you are burning more calories in general, then you need more of them to fuel your body efficiently.

You have plenty of time to lose that weight.
All the best.

What did you set your goal to on mfp? Healthy weightloss is between a 0.5-2 pounds a week, if you're planning on counting calories for the next 8 months you could set it to 1 pound a week on mfp and see what kind of calories it gives you.
I feel like when I drink more water I lose more weight, but that could just be because if I'm making an effort to drink water I'm probably being more health conscious anyway. I try to meet the mfp goal either way, it's good for your skin, liver etc, even if it doesn't aid weightloss.

There's a big misconception when it comes to a caloric deficit. It's not anybody's fault. It's just that people haven't really been taught. So, here's a rather simple explanation:

The body uses food for absolutely everything it needs to function, most importantly, recovery. Progress is always made through recovery, but if one is not eating decent amounts of food, their recovery is slowed, thus their progress is slowed. Then just how does one ensure progress on low calorie diets? Well, you exercise to create the deficit! Not eat to stay within the deficit. For example, Michael Phelps used to eat a 10,000 calorie diet, and would train excessively, but still remain with enough caloric intake at the end of the day to spark progress. If you consider doing this, here's an example: Imagine someone with a 2,000 calorie diet. Their goal is to, at the end of the day, have eaten 1,500 calories. To do this, they train enough to burn 500 calories. BUT, to make this easier, you could subtract 100 calories from the original 2,000 calories, leaving you with 1,900, and only have to train enough to burn 400 calories. That way, you're results from training can be kept, whilst slimming you down, and leave you with enough calories at the end of the day to recover.

It is often a mistake of people's to ignore this because they want to get results faster, but there are a variety of reasons this method of reasoning can be rather ignorant at times: 1.) It is popular to reduce carbohydrates because it seems to be the quickest way to lose weight; while that seems correct, the truth is carboHYDRATES help with keeping the muscles and body hydrated, meaning, when one lessens the consumption of this macronutrient, the body holds on to less water. The truth is you can see results with a low-whatever-macronutrient diet as long as you practice good eating habits, and are training properly and with intent--it just won't be as apparent within the first few weeks. 2.) When the body is not getting enough food, it begins to store energy in the form of fat to compensate for what you're not allowing it to get. This is why people in developing countries with not enough to eat can often be seen with distended tummies, or why overweight people who jump right into eating exponentially less without prior research never seem to lose weight and give up. 3.) Progress is made through recovery! This isn't so hard to understand, it's just one of those things that's hard to accept when you're desperate about making progress. To make progress, you need to recover, to recover, you need food, but not just any food. You need food the body can use to help it with it's everyday functions. If this confuses you as you're new to this, I think Jujimufu said it best, "Just eat foods no one argues the health benefits to."

Another thing is water. Water is life, literally, and is so much more than a form of cleansing and hydration. The body uses water to carry nutrients and oxygen to the cells, helps the body absorb said nutrients and oxygen, it cushions the joints, moistens oxygen for breathing, protects and cushions vital organs, helps convert food into energy, regulates body temperature, composes 75% of the brain, makes up 83% of all blood, removes waste, and accounts for 22% of bones, and so much more!!! You're doing yourself a disservice if you're not making it a habit to drink water as consistently as possible. A good way to begin developing this habit is to drink two cups of water in the morning first thing upon waking up. That is when the body is most dehydrated after having slept without sustenance for so long.

Also, sleep. Sleep is the ultimate recovery.

A popular way to lose weight and burn fat amongst many bodybuilders is a thing called carb cycling. It can be as simple as this, please don't over think it: eat less carbs one day, more carbs the next. Frank Zane, considered to be the most aesthetic man ever, would eat less carbs for three days, and on the fourth, more carbs.

I'm giving you options here because there is a... misconception that what you're doing is how to lose weight. It can be... But it's not something that can be done everyday for the rest of the year with consistent progress. Eventually, on low calorie diets, the body learns to outsmart what you're forcing upon it, and finds way to get you to give it what it needs. Furthermore, the scale is a liar! But hips are not. Hips don't lie. For example, I used to weight 73kg, and no, I am up to 95kg, but still be able to wear the same clothes. In fact, the clothes from when I weight 73kg now fit a tad to big. This is why it's important to train if aside from health, being happy in your own body is something you strive for. You should consider lifting weights. Women can lift weights. They won't get bulky or masculine. They'll actually get tighter and clothes will become more form fitting, but the exercise discussion should be left for another day.

The point here is not just to help you on your journey. You have from now until September, and it shouldn't be about only being able to fit in the dress. It's about being able to feel good in the dress.

I hope I've been able to help. Everyone can offer you advice, but at the end of the day, absorb what is useful, reject what it useless, and add what is essentially your own.