Help with social anxiety?

[Nick]

I'm going through social anxiety (as well as depression), and I don't have the money to see a therapist, nor do my parents. I'm a junior in highschool. My biggest fear is public speaking and it's a big contributor to my bad thoughts, like it helps make me think about not wanting to live anymore. As well as the fact I'm nervous around people and hesitant to speak up. I'm not suicidal but it feels as though I'm taking the steps mentally to get to that point. Is there something I can do? I don't have many friend to vent to but I have a secret tumblr and twitter, tumblr for journaling and twitter for like the smaller stuff. I used to have a therapist and was prescribed to medicine but I don't think it really helped. What can I do?