I know exactly what you are talking about. I was completely homebound for almost two years from 94-96, and due to a pretty major setback am now dealing with agoraphobia again...haven't left the house in about a month. I, too, get those feelings and thoughts that I want to go out. I won't go alone, so if they come when no one is here, I will at least go outside, take the dog for a short walk or walk around the yard a bit. When someone is here, I try to take advantage of the feeling even if all we do is go around the block. It always feels so good to have the desire to get out, I hope it's that way for you too.
Just a positive note for you, after being homebound for two years, I slowly started to get out, first just short car rides working up to going into a local store and then onward to larger places and farther distances. It took me a long time, ( I did do it without therapy, which probably would have speeded the process up alot) but I got to the point where I could anywhere I wanted, anytime. Like I mentioned, I'm dealing with a pretty bad setback now and am not getting out, but have found a therapist who will come to my home to help me. I will start with her next week and hopefully will bounce back much more quickly than last time. So there is hope!!! It's not always easy, and it takes patience, but you can do it. Start with very tiny steps and don't think that because they are small they are not doing you any good, any time you put yourself in an uncomfortable situation and manage it well it a step in the right direction!
Wishing you the best!