Dear Loana,
I know how you feel. I remember when my baby seemed to get sick, my first thought was, "I hope I won't have to take her to the doctor." (I just posted a message on the Introduce Yourself board, if you want to know more about my story.)
This does not in any way mean that you are a bad mother. So what if someone else has to take your son to the doctor? He would have been far worse off if he had a non-agoraphobic mother who hit him for no reason, or humiliated him, or abused him in some way. You can be a good mother, even if you don't leave your home (as long as you make sure that someone else does take your son to the doctor if necessary). The main thing is how you bring him up, what you teach him, how you make him feel like an independent person, valued and respected for who he is. Anyways, I could go on about parenting, but that's not the point :).
Of course, you should still try to get help, and hopefully, get better, but don't feel guilty about where you are, at any point in your struggle with panic.
Judy