I would seriously see a doctor? Are you healthy? You don't sound healthy considering you drank so much of that poison. Any cola beverage is like drinking acid. You could be borderline diabetic, my nephew was like this he drank like 10 cans of coke a day. He almost died you need to get to a doctor asap. I don't think this is earth changes. We're not doctors on here. Your body is telling you something is wrong, you could have high blood pressure, which causes all the symptoms you're explaining, or you might have a heart attack. A co-worker was like this no appetite, stomach pains, dizziness then bam she was dead from a massive heart attack.

Not trying to scare you but you need to get to a doctor. And perhaps see a specialist about your agoraphobia. I used to be like this though not so extreme you can cure yourself, you could even be having panic attacks. I would suggest getting off the internet and off a doom site and getting some fresh air, walks do wonders for the well-being :)