@OP - You have to just get out there. Working is good way to meet new people especially the crappy jobs. In crappy jobs people tend to be chatty to relieve the stress of real life and in a crappy job there's a lot of common ground mainly working at a shitty job.
As one of the posters noted you have to just get out there and not be afraid to make mistakes. We all do dumb things, we are all embarrassed about one thing or another, we all have things we want to hide, so in this respect you are no different than anyone else.
Loneliness really sucks but the cause for it is really your own inaction. Till you actually get your ass out of your chair and face out into the world you are going to remain lonely.