There is something horribly wrong with me

Has anyone ever had this or heard of something like this? I'm going to the doctor in a few days but I'm so impatient for an explanation. And no, I'm not pregnant. I've done the test.
Without changing my diet or exercise in the slightest, I've been putting on an average of two pounds a week. And even if I gave up exercise and ate nothing but junk food I don't think I could gain quite so much so quickly. And the strangest part is I'm only gaining on my stomach, and I have been very overweight before and it usually distributes evenly over my entire body as I'm an hourglass shape. I've started eating healthier and exercising more to lose this weight but I can't even maintain it. I just keep getting bigger. I poop an average of three times a day so it can't be just a slow metabolism. And when I go to the bathroom it never seems finished, there's always a constipated feeling. I also have a constant stomach ache and barfiness.
This is all really starting to cheese me off, especially the weight thing because I only have one dress I can fit into. None of my pants are even close to doing up.

 

It sounds like it might be Irritable Bowel Syndrome. I agree with Blackie that you should make a doctor's appointment.