Really need some advice

I am not here for sympathy nor am I here to argue as seems to happen every time I post a topic. I have a legitimate question that needs a legitimate answer. Some backstory will be required so here goes.

Earlier this year, I finally got to the point that I had to take my calories down to well below 1200 to lose weight because my metabolism is so bad. I have never been diagnosed, but I strongly believe I have hypothyroidism. When I first started, I weighed 450 pounds and I was told by MFP to eat 2450 calories a day to lose 2 lbs a week. I did this and gained a ton of weight. I brought it down to 2000 calories a day. Still gained. Finally took it down to about 1800 and stayed steady so I finally brought it down to 1650 and started to lose weight. Slowly but surely, I've had to decrease my calorie count until around January, it finally went down to about 700 a day. This is all on top of exercising over an hour 7 days a week. Walking is the only thing I can do due to tremendous hip and back pain and even still, I hurt like crazy when I stop.

Anyway, I lost weight steadily until about 2 weeks ago. I didn't hit a plateau, I hit a wall. Pure and simple. 700 calories a day and 72 minutes of exercise a day and I couldn't lose any more weight. At the advice of a friend, I decided to try upping my calories to the minimum 1200 and drinking more water. He used an analogy about cars not having enough fluids to run properly that I can't remember at the moment because my mind is hazy right now.

Now here's where I need some advice, since increasing my calories to 1200 a day, which has been a real struggle trying to find calories that aren't loaded with sugar or salt but I've done it. I also started taking a multivitamin as well as a Cinnamon supplement for sugar metabolism. What's strange is that since doing this, I've felt absolutely terrible each day and it gets worse and worse each day. I can't think clearly most of the time. I hurt worse than ever. I feel bloated and very gassy. I have chest pains which feels like air pushing in my chest and trying to get out and at this point when I get on the treadmill, my chest feels like it's gonna explode 90 seconds into my workout. Starting today, I've developed a constant feeling of a lump in my throat to the point that my airway feels like it's gonna close any second.

I need to know what I can do about this. Seeing a doctor is out of the question as I'm unemployed and have no medical insurance. I just can't understand why increasing my calories has made me feel so much worse. I keep track of my vitamins and mineral intake and since increasing the calories, I've started meeting all my vitamin needs, with the exception of iron which I still get about 60% daily. I also am down to less than 1200 mg sodium daily and I'm usually less than 50 g sugar and of that 50 g, anywhere from 40-45 of it is natural sugar from fruits.