Yes, this has happened to me. I am at a conflict with myself. I want to have friends and the normal social life but at the same time I am a loner and prefer to be alone a lot. I don't know what to do about it. I do the same thing you do, not show up or come up with an excuse not to go. I think for me it has a lot to do with my childhood and being abused. I don't want to let anyone get close to me because all that have ended up hurting me in the end. But, that's me. I wish I could help you out and say some magic words that would make everything normal for you but I can't
All I can say is keep trying. Never give up if it is important to you. Maybe one day you will find the right person that you can relate to and be close with.