Hey. I've got slight agoraphobia as well.
It used to be a lot lot worse a few years ago. I never wanted to leave the house, even just to go with my family to the cinema. I also started skipping school because I didn't want to go outside.
I never got any help for it. I just decided that I needed to get over this and I forced myself to go outside. It wasn't a very pleasant thing to make myself do though.
Maybe you could try talking to a counsellor or a friend about this? I think gradually getting used to going outside can help but it's better if you have someon to talk to about it, share your progress etc.
Anyway, that's just my opinion. Just know that you aren't alone, there are tons of people suffering from agoraphobia.