Do i have social phobia and how can i help it?

hi my name is dave im 19. all my life i have bin shy and afraid to be myself around people. it has gotten really worse when i moved from nj 2yrs ago 2 atl. i had not talked 2 any 1 and when i did talk 2 people i aways blush smile or stutter so when i talk i try 2 keep my answers short or just stop talkin or nod my head. people say its scary how quite i am and i have no reason to be shy. i had girl freinds and i did not talk 2 them on the phone because i think i will sound stupid on the phone or it will b a really boring convo because of me so we just IM eachother all the time and thats how i get my feelings out 2 her or if im around her i write on a peice of paper and p it 2 her. last yr i lost my virginity 2 my 1st GF with out even talkin we were 2gether 5months with out even talkin.. ive also started smoking last yr to cuz i remember i was high wen MJ died, i get high alot im high as im writing this on some kush and i had a vicodin pill... i havint told any 1 i have a phobia because every 1 will judge me. i also dont like 2 read in front of the cl 4 that same reason. that is also the reason i dropped out of college. i stay inside every day and watch youtube videos of people whos doing better in life den me just because there happy 2 be there selfs. i think that my life is pointless and its going 2 waste. some 1 please help me i want 2 get better and live