Welcome to the forums.

That diagnosis of depression can be scary. I'll never forget how scared I was when I got mine. I, also, often find myself seeking solitude but when I get it, I find myself feeling down, too. I find that it helps to talk about it. Sometimes (when I'm afraid of discussing it with a person) I'll even talk to my dog about it just to get the words out. Have you tried keeping a journal? That helped me when I was first diagnosed.