Isolation

I am an isolative person. My tendency is to keep myself and my thoughts to myself, to not conncet with people on more than a superficial level. Alone is my zone of comfort, the state I have found myself in most of my life. When I was little I isolated in an imaginary world made of books and characters in my own head, letting only a select few into it with me. I am afraid to let people in to my world even now, fearing what they may think of me, fearing rejection and connection both. If I don't ever let you in, you can't hurt me. If I don't make the effort to reach out, then I stay comfortable. But I also stay lonely. And I am lonely now, here at treatment.
At the same time as I withdraw from people in fear, I long for deep and meaningful connection. I think everyone at some level wants to be known, accepted, and heard. I've just spent much of my life denying that truth for myself, thinking I was ok on my own. It isn't really true. I am alone, and I have myself to blame. I push people away and they get tired of trying to reach out to me when they constantly get a negative response. I didn't know for a long time that I put up such a wall. Many times it's just my automatic reaction. Something in me says not to get vulnerable, not to reach out, to stay safe and superficial, living alone in a bubble.
God made people not to be alone, I have heard. He made them for relationships, with others and himself. I'm not in that sort of relationship with him now, nor many others. I don't mean to minimize the friendships I do have. They are all dear to my heart. Yet my greatest fear, to be known and to know deeply, is also one of my longings, and it is not yet fulfilled. I am paralysed by the prospect of approaching relationship -- I freeze, hide, and the wall goes up. It's my MO, so to speak.
So today when I met with members of my treatment team and they challenged me to approach each of my peers and ask them three questions, I freaked out. I don't want to do it. Since it's a challenge, it can be refused but it looks bad if I do. It says to them that I am not ready to surrender. I don't want to give that impression out, but I'm not sure if I'm ok with letting go of my isolation. As lonely as I am ... well, this is what I know.