jmodge,
I'm sorry you're having such a hard time. I am, too, so I know the feeling...
Don't be afraid to go to a doctor. All they will do is help. I've been going to psychiatrists since 1996, and they made a world of difference. I've been on Prozac since then, and it's calmed me down a LOT. I still have outbreaks of panic and depression, but they're not all day, every day like before.
I think your light-headedness is a result of panic, as is the heavy feeling in your arm. I have it in my legs, sometimes, it feels like I have to struggle to move them. But it's just panic, and it will pass.
I'll write more when I get a chance. It'll get better
Take care.
