Hi Mandy,
First I want to wish you a warm welcome. I'm sorry to hear about your condition, that's really a bad condition, It's called street fear. But I think you might have it as in agoraphobia style too, like that you are afraid of the open air? I mean, there are ppl with that phobia. Or is it just the people? I'm so sorry you are going through this, that must be a horror situation.
I will give you some advice, and I hope that it will help you get further.
And about people, I know you would be afraid of what people think, but street fear is extreme but still people should be taking care of how you feel, the fear you have is very undescribeable, but still there is a way out! And please find people who can comfort you and support you!
At first, you should sit and relax and think if you are really having something ''serious'' most people with panic attacks make them up, because when you're worried about that, you will feel it. Just when you think you are starting to have a headache or getting sick, you will get sick (some ppl really can affect themselves so much!) So, Mandy, please be strong and know that it might be just a weird feeling, bodies can be strange, I know! But still you should try to comfort yourself by the thought, It will go away and I will be more at ease and I'm not gonna help myself by thinking all these weird stuff....
About the E.R, you can always call them, just give them a call and they will come to you, tell them how much you are concerned and in how bad state you are, I mean, if you can't get out of the house you need serious help so maybe instead you should call some instants who have the specialty to help people with Agoraphobia/Street fear or Severe social anxiety. The best instants could stop by your house and talk with you inside the house and get things on order what you are going through and you will feel more at ease with a nice therapist, though some places you really should visit, but i'm sure,in your case, anybody would wanna help you (if their any good).
Your anxiety level must be extreme skyrocket high, so please know that it's your anxiety driving you insane, not your body, not dangers, just fears... I know, just fears are easy to say but still big monsters, but believe me, if you could calm yourself down more easily, you will get there really.
It's just hard to believe and hard to get, but when you get the cause of your fears and the root how you can calm down your system, things must work out again.
Though, I know you would say, but How? That's what everybody wonders, you must believe, that nothing worse will happen outside, the fear might be a ''feeling of the body and the mind'' but from heart you don't wanna be so fearful so your will , will get you out of this state.
Good luck, please keep us informed.