First, what is your calorie goal? MFP recommends no less than 1200. Even 1200 is too low for most people.

You are just starting out. Don't give up on the first day. Realize that this is a learning experience and you may need to readjust your thinking. Just eat moderately the rest of the day. Yes, you will be over. But you need to give you body the nutrition it needs to keep going. If you can, try to fit in some exercise. It will be good for you, plus you can get some of those calories back! :-)

One thing that has helped me is logging as much of the day as possible the night before. It gives me a good estimate, so that when that craving hits I can see how much leeway room I have.

As far as low calorie foods, I would say it isn't all about the calories. Some foods are more filling than others or have better nutritional values. It is important to have a good balance of protein, carbs and fat. I personally, have found I need carbs to start my day off, otherwise I am hungry throughout the day. I also notice I am more "snacky" at night, if I am not close to my MFP recommended daily protein goal.

*Oats are very filling and make a great breakfast option, topped with your choice of fruit, nuts, seeds, nut butters, milk, etc..

*Salads, sandwiches, wraps, etc. can all be possible lunch and dinner options depending on what is in them. Go light on dressings and cheese.

*Measure! Measure! Measure! It is easy to underestimate or overestimate on portions. If possible, use a food scale as it will give you the most accurate amounts.

*Drink plenty of water. Sometimes we think we are hungry when we are actually thirsty.

Hope that helps!

I know what you mean about not realizing how much you are eating. That is why logging on MFP is so great! It is a learning experience so don't get discouraged, this all takes time to figure out. It is all about finding the right balance for you.

How did you come up with the 1200 goal? Unless you are very small in stature and build, this is probably too little of an amount for the 25 pounds (according to your profile) that you want to lose. Most doctor's will tell you a 1/2 pound to 1 pound a week is really the most you should lose per week. This also depend on the weight you are starting at and how much you realistically need to lose. Oftentimes, slower weight loss is more sustainable and realistic than quick weight loss.

Food -
Depending on the brand of Ranch dressing, 2 T of Ranch can be between 110 and 140 calories. If you don't want to switch dressings (alot of fat free aren't that great), then just watch your serving size, perhaps try getting by with a T. at a time. You may be surprised with how little you actually need. You always can try other salad dressing options. There are a lot of salad dressing recipes too. Just google "low calorie salad dressing recipes" and more than likely will find some ideas.

I am not by nature a morning person, but have realized it is important for me personally. You can find all kinds of breakfast options and ideas on the recipe forum here on MFP. Here are a few examples, the calorie amounts are based off of the brands and amounts I use:

*40 g (scant 1/2 cup) oats cooked with water (150 calories) topped with a small banana (110 calories) sprinkled with 1 t. brown sugar (15 calories) and cinnamon (less than 1 calorie) = 275 calories (You can also buy the instant packets, but I like making my own combinations that way I know what is in them.)

*slice of toast (mine is 80 calories) with creamy peanut butter (1 T = 90 calories) = 170 calories total

*1 or 2 Homemade bran muffins = calorie would depend on recipe, add-ins, etc. Here is the recipe I based mine off of: http://www.food.com/recipe/low-fat-but-tasty-buttermilk-apple-bran-muffins-ww-friendly-101631

*2 hardboiled (or scrambled) eggs (70 calories each x 2 = 140 calories) with a slice of toast (80 calories) and 1 t. butter (1 t. real butter = roughly 34 calories) =254 calories

*medium size flour tortilla (120 calories), 1 scrambled egg (70 calories) = 190 calories + choice of veggies and other protein.
These could be made in batches and frozen so all you have to do is microwave for 1-2 minutes

You could divide your calories up equally between all your meals/snacks or you may decide that you need a bigger breakfast or supper, thus would divide your calories accordingly. With your stomach being so sensitive, eating smaller amounts 5-6 times throughout the day versus three large meals may be helpful. Everyone is different so you have to do what works for you.

Have you tried non-dairy alternatives? Not only would they be gentler on your stomach with you being lactose intolerant, but a lot of times they are lower calorie.

Exercise-
YouTube or your library may have some exercise dvds. Google also is always a wealth of information. I have asthma so can relate to getting out of breath. Maybe start with walking?

Some other exercise options:
*http://www.active.com/fitness/articles/10-minute-cardio-blasts-that-you-can-do-anywhere - I haven't tried these exercises. But they look similar to the exercise app I had on my old phone (can't remember the name but loved it and miss it)

*http://www.nerdfitness.com/blog/2009/12/09/beginner-body-weight-workout-burn-fat-build-muscle/ - This isn't a calorie burner but is just as important.

*Quick Fix Total Cardio - I think some of the routines may be on YouTube, but I used a dvd from my library. If you normally run out of breath quickly, don't be surprised if it takes couple times before you can do the ten minutes without stopping, but it is fun!

Water -
I would suggest trying stayfitchic's suggestion about infusing your water with fruits. There are water bottles or pitchers with an infuser, or you could just throw your fruit straight in with the water if the texture doesn't bother you. What about drinking Gatorade? Your skin not bouncing back, kidney's hurting, going to the restroom infrequently, etc. are issues that more than likely related to being dehydrated. Dehydration can be serious and cause a lot of other health problems so you definitely want to get on top of that! When you are dehydrated you are damaging your entire body, it can even affect your mind, equilibrium, eyes, etc.. If you were hydrated consistently, I wouldn't be surprised if your stomach would even feel better over time. If you aren't drinking enough liquid, it isn't too surprising that fiber would not agree with you.

Basically, a balanced, consistent diet of nutrients and water is important whether trying to lose, maintain or gain weight. It is great that you are trying to conquer this now while you are still young. You can do this!