It sounds like you have agoraphobia. I can completely relate. I haven't left the house in about 2 1/2 weeks & would go even longer, but I'm going to have no choice within the next couple days. I always wait until nighttime to get the mail because I'm usually too afraid to go get it in the day. I haven't even gotten it yet from yesterday (Saturday-- it's almost 1am on Sunday night/Monday morning now) Sometimes, I go weeks without taking out the garbage because of it. A lot of times, it's worse than it is now. There are times when I can't leave the house at all & never get the mail, grocery shop, or do any of the things I have to do.
Medication may work for you, &/or therapy. Sometimes, all people need is therapy, but for me, I find medication does far more good. I can leave the house now, if I have to, most of the time, as long as I take my medication beforehand. It sounds terrible, but, for me, it's better to be dependent on medication than to never leave the house at all, especially since I have to do certain things outside the house. At least the medication makes it more bearable for me to leave.