How i stop being shy?

I dont have many friends and im very soft spoken. Every time there is a sub i dread it because i have to scream "here" and pray they hear me. Most of the time people have to speak up for me. I spend most of my day being quiet and have about 1 friend in almost every cl that i can tlk to. When i try to talk to people i feel i am boring them because i never know how to respond to what they say i usually say "ok" shake my head or give a little smile. This makes people stop talking to me. People dont see me as geeky or a loser they say oh your so quiet and nice awww. Alot of people think im adorable but never wanna be my friends. Im a freshman and i really wanna make friends before softmore year because of something terrible i did i need friends there so it wont be awkward. If your willing to give me advice about the terrible thing i did email me @iheartsupermac18@yahoo.com. Thanks