Do i have social anxiety disorder or depression....both?

i am 17 and for a few years now it has been getting worse. its very inconsistent though. some days i am very quiet and wont talk to anyone or am too nervous to talk to anyone but then rarely there will be a day where i can talk to almost everyone without chokin my words. ive noticed that my skills and coordination are very effected by this too. i am waay worse at everything when someone is watching me, especially a girl. i used to be sooo good at skateboarding, pool, pretty much everything. but i just suck now because while im doing these things all i can think about is them watching me and i do horrible. ive recently been constantly fearing what people think about me.last night i noticed after drinking a few shots i was doing awesome at pool becuase i didnt care about anyone else. i was making all the shots im capable of. which usually i know im capable of and should always make. I am CONSTANTLY talking to myself in my head, all day. i take valerian, st.jons wort, 5-htp, anything els