How to be less socially awkward?

I'm 20 and feel very socially awkward. Some days I have trouble talking to my close friends and when talking to people I don't know well I stutter alot and have trouble getting what I need to say across. I hate talking to people because I know they just think I'm weird. I wouldn't say I'm shy, more anxious and awkward. I find myself unable to move on from things such as relationships and a guy I went out with said I was awkward because of things I said and did. How to I become less socially awkward and shy?