What do you think?

You need to track your food intake. Here is what you do.

1) Open your diary to the public.
2) Log your food.

I guarantee you that you are eating too much. The whole "I ate 600 calories a day" thing doesn't cut it. If the doc says there is nothing wrong with you then calories in vs calories out applies.

It's not difficult. Log your food...eat under your maintenance and you will lose weight.

i agree with the above, open your diary, log your food, be consistent, be precise. Get a food scale and weigh your food. Stay at it vigorously and conciously for days, weeks and months and if you have any questions or things don't seem to be going well? Come back and ask more questions with your diary still open so we can help you out mid-track. Best of luck.

Agreed with the above responses. Good ideas. Log everything. There are calories in nearly everything, so be very diligent.

Also - Cut more calories. Eating less always works. Don't go so far as 600 cal/day... Get a baseline of good logging of food/quantities, and you should find a balance where you start losing weight. It is possible to eat very little and still not lose fat. You need to force your body to use stored calories due to your eating less than your body needs. So long as you are above essential body fat levels (10% to 13% for women), your body will burn fat when you have not eaten enough during the day. For me, I know I am burning fat when I feel hungry 2 - 3 times during the day before meals (and then I wait a bit before the meal or snack).

One sure way to start losing fat is to eat below your BMR. You can calculate your BMR here:
http://www.bmi-calculator.net/bmr-calculator/

Put in your stats, and check your BMR. This is the amount of calories your body needs if you do nothing all day but rest. You can add activity multipliers (20% up to 100%) depending on how active you are during the day (excluding exercise), but if you eat at your BMR or slightly below, and you have more than the minimum essential body fat amount (5% for men, 10% - 13% for women), your body will use stored fat to make up the calorie differences.

3,500 calories = 1 lb of fat. If you have a daily deficit of 500 calories/day (equals 3,500 calories per week) under the amount of calories you burn, your body will convert 1 lb of stored fat into energy.

If you eat below your BMR, don't go more than 250 cal/day below - that would put you at a 0.5 lb/week deficit, PLUS a deficit for not adding your activity multiplier (at least 20% of your BMR). For the first 2 - 4 weeks, try eating at your BMR and watch if your weight starts going down.

If you go over today, try to go under tomorrow. Splurge for Thanksgiving (a little bit), then skip breakfast on Friday and eat a small lunch and dinner to try to balance your excess. Look at your weekly calorie intake graph (on a mobile device, I don't think it's online) and it will tell you how much you were over or under your goal for the week on Sunday. Always try to meet your goal at the end of the week, and don't stress if you go over one day.

And calorie estimates are ESTIMATES. So if you are not losing weight and meeting your goals, then cut more. You will find a place where you will start to lose fat. Be patient and look at overall weight trends, not day to day fluctuations.

Good luck! Don't get discouraged. You can do this!

And do eat back your exercise calories, or at least part of them. Just living you burn about 80 cal/hour (divide your BMR by 24 hours). So while you may burn 500 cal doing 60 min of exercise, really your additional calorie burn is more like 500 - 80 = 420 cal.

If you are not feeling hungry after a cardio workout, push off your next meal or snack longer... It's okay.

To me it sounds like PCOS or a thyroid issue - I would suggest telling all of this to your GP and asking them to run checks.

Despite exercise and a great diet, people with these issues (especially thyroid issues) can gain weight as your thyroid directly influences how your body uses the food you give it.

Hair Loss can be attricuted to these things - however, hairloss on a 600cal diet is not uncommon at all - and how quickly it happens depends on the individual - however - if it was no a 'nutritionally complete' 600cal diet - losing hair will start much quicker.

I suggest seeing your GP before such extreme dieting again - if you do have a hormone issue, extreme dieting can be one of the WORST things you can do in the long run.

I do understand your frustration - especially since there is so much information out there ("eat carbs!", "don't eat carbs but eat fat!", "Eat fat but don't eat tomatoes!" etc), and you really don't know what to do.

I've not been on here that long, about six months, but I can tell you that there is sound advice here on MFP. Just looking at the past few days i see a lot of eating out, which is a lot of sodium and fat. I don't know how much you are actually burning at the gym - those "gym computers" are not very accurate, neither are the MFP estimates. So it's a possibility that you are underestimating your intake and/or overestimating your exercise, which, combined with too much sodium could lead to you not losing/gaining.

here's what you do:
start today by weighing everything you eat. don't guess, don't 'sort of'. weigh everything.
Log everything you eat.
exercise is important but you are going to lose the weight in the kitchen so that is where your focus should be.
try to eat real food that you make - fresh salads, fresh fruit, chicken etc.

you can do this.

Had a look at your last few days, and I noticed too that your sodium levels are high, that could cause you to hold on to water. I was in a similar spot a couple of years back and it turned out I was ill.....didn't know this until I was in pain! now on meds for ulcer and IBS since getting that sorted and joining MFP and eating sensibly I have lost a lot....I believe mainly water from my poor swollen guts that were so inflamed and irritated. Go back to your doc as losing hair is not right....I did but that was due to my iron levels being almost zero with my ulcer.

Are you weighing all your food? I noticed a HUGE difference in my portion sizes when I started weighing. What you think is a portion can quite easily be double what a portion should be, which means double the calories.

You need to persist until you find a Dr who will - even if it means going to a naturalist or an integrative practitioner - who doesn't look at masking symptoms, but fixing their cause. Your health is worth perusing & if you say a Dr doesn't take you seriously, then, it sounds like you know already it may be more than just your diet and exercise - Its worth finding one who will

some thoughts/suggestions

6 ounces of chicken seems pretty tiny. That's like 1/2 a breast. You're certain that you're tracking accurately? It looks like you eat out a lot, and if you're not eating out then you're eating the same old thing at home. Its much easier to control what you eat if you're cooking more.

TBH I find some entries hard to believe - two slices of a big cheese pizza has to be more than 340 cals. Americans pizzas are HUGE and I know that our much smaller serves are usually 200cals/slice. Anyway. I flicked through a bunch of entries and it was pretty much:

breakfast - eggo waffle & chocolate almond milk

lunch - either chicken & frozen veg or some kind of fast food

dinner - either chicken & frozen veg or some kind of fast food

Get some variety in there

ALSO you seem to just use a bunch of 'homemade' recipes that are in the system. How do you know what they put into their recipe? Try entering individual ingredients or creating your own recipes. And maybe try to get a bit more creative in the kitchen. I'd be put off eggo waffles (whatever they are??) for life if I ate them every single day.