Should I just not try anymore?

i have trouble talking to girls. When I do end up talking to one she ignores me. Like we do start a good convo but somehow the girl likes to take her precious time in replying back or not reply back at all. I only talk to them through facebook, i dont even text them nor talk to them in real person. How am I going to text them if I can't even get that far into asking for their number! the worst part is that they do see the message I send (because it automatically shows the check mark on face book when someone does see a message) and they are connected or they post stuff on facebook and just ignore the hell out of me! are all girls like this? I just want to talk, make a friend, hangout. Im not a creep, I am just a 20 year old friendly guy trying to make friends to not feel so lonely...I dont just send messages to random girls either, I start messaging girls that like my status or comment on my stuff.