Why am I constantly malnourished despite eating a balanced diet?

[anonymousc17]

Hi,

I am adamant I have some kind of malabsorption condition although my current GP has pinned all of my symptoms down to chronic fatigue, which I do not believe can really be the case. I lose weight ridiculously quickly when eating a normal amount of calories (2000) with a good ratio of macro's - I usually eat about 60% carbs, 20% fat and 20% protein - throughout the day. Probably useful to mention I am a 21 year old female. If I lose weight, my stomach becomes very bloated, my hair goes limp, I get depressed, my tinnitus gets a lot worse and I feel itchy, I get terribly dry skin etc. However, I can counteract this by eating about 3,500 calories a day, and within a few days all of the prior symptoms completely disappear and my weight seems to stay put. When eating around 2000 a day, I feel very sick throughout the day as well and as though my stomach is quite empty. I poop loads and am constantly bloated etc. and have a lot of gas. I had a blood test done and nothing out of the ordinary was found apart from low ferritin. I eat a very good diet, eating lots of meat, eggs and green vegetables. I got prescribed iron tablets recently but they have little effect unless I am eating a vast amount of food. Last year I took antibiotics for a tooth infection and a lot of my symptoms did seem to disappear, although it seems to have come back. I was wondering if I had some kind of bacterial intestinal overgrowth preventing me from properly absorbing food - as my GP does not believe I have this she refuses to prescribe me more antibiotics. I would like to upload a picture of how badly my lips look on a day of eating healthy food consisting of 2000 calories - by the end of the day they're black at the corners and I end up looking very ill, despite how well I am eating and I drink plenty of water. 

To view the pic follow the link: https://ibb.co/na4Lyv