Honestly man, get out the house...enjoy your life, stop sitting in front of a computer and barricading yourself from the real world. Computers should be an addition to someones life...not thier actual life. What you are doing is not being social, its being dependent on a monitor and keyboard and a mouse to make you happy, instead of going out and doing it yourself.
What the hell are you wanting to get married for at the age of 20?! And to a girl you have never met?! Mate, for all u know she could be 14, she could be 30, she could have 2 heads, she could be married...i could go on and on and on with what she could be lying about. And therefore this comes to my point that she was playing you...after attention, wanted to have a lad chasing after her...so she plays on your insecurities and feeds you all this crap about getting married and wanting your kids...
...and you must have insecurities about being alone and getting lonely etc because all the lads i know would run a mile if a girl they had known for 5 months started talking marriage and babies...let alone a girl they hadnt even met!
You said u were not like this before u started speaking ot her...but how do u let someone manipulate you through a computer screen? You need to look at yourself here and go get yourself some professional help. What you have here is an infatuation, something which covers up the unhappiness you are feeling inside yourself. While you are concentrating on this you do not need to work on you.
******* 7 Times World Champion Michael Schumacher - the ultimate sporting hero *******