I was a big loner in all levels of school. I am socially awkward - in that I feel like a fish out of water when I am with people - especially people I do not know. I use to think something was wrong with me... my mother still thinks there is something wrong with me. But as I have grown up and as I have gone through therapy I have learned that if I am ok with who I am and I am not hurting myself and others then there is nothing wrong with me.
Let me ask you something, do you mind being a loner? Meaning if your mother, or others in your life were not telling you it was "wrong" would it bother you being a loner? If not then I say be who you are. You, and only you, have to live your life. As long as you are the best you, you can be then who has the right to ask anything more of you? If you don't want to be a loner and you want to be more social and have friends, then I suggest bringing that up with a T or guidance councilor. They can help you work on things to help you in your quest to be the best you, you want to be.