Alone?

I have found myself in a rut. I have very few, distant, friends. I rarely talk to anyone and have shut myself off to the world due to a mix of anxiety, family issues, and social awkwardness. I'm going into the last year of high school and I feel like I'm failing at living. I'm surrounded by wonderful outgoing people in my family and daily life but they never seem to have time for me. I feel like a second choice for people. I feel alone and I don't really know how to fix it...

P.S. I just reread this and wow I sound sad. I would just really appreciate some advice.