Curiosity killed the cat.
This might be easier said than done, but part of NC is to avoid reading her messages. If she sends you a message, delete it before reading it. Or have someone you trust help you delete it, so that you are not tempted.
Reading her messages will make you over-analyze and go in circles. Furthermore, if you respond, you're going to add salt to the wound. If she responds to your reply, you're going to over-analyze again. If she doesn't respond, you're going to sit and wonder what went wrong again.
NC is to help you break this cycle. Cut all contact, so that you don't add to the confusion any more. I strongly suggest you read the stickies that we've mentioned. Especially the ones about NC.
Finally, your friends are right. Go out. Meet new people. Have fun. Enjoy life.