No, DO NOT EVER say 'I love you' to her straightaway!
I Love you works only when the guy is already a good friend of the girl or the girl already has a crush on that stranger guy.
Always think from the girl's point of view. Since you love her without knowing too much about her (only 5 months) so I think most likely she's quite pretty or cute or both, due to which you've fallen in love with her. So chances are that there must have been many guys who had already approached her and said I love you. Whether in real life or over the internet. It's Pakistan, it's how these things work here. Pretty and single girls are v hard to find (sigh). She must have said no to most, (obviously she can't give a positive response to everyone). So when you go to her and say that, she may just think ok another one of the desperate lot.
Just try to catch her attention by being nice and friendly first. Whether through common friends, or through noticing how she responds when you look at her. If she also looks at you, then it means you have some chance. Be her friend first, no matter what it takes, work on that. Once you become her friend, exchange numbers or internet ids and start slowly. SMS etc are fine. Just be a good caring friend and then make her feel special without saying i love you.
If you remain nice, she will herself tell you that she loves you. Even if she dun say that, she will be waiting for you to say the magic words. Till that time, just work on being her good friend.