Some people like to hear new stuff once in a while, and when you told them everything about yourself it can happen that you get "boring" and they either don't talk to you so much anymore or stop completely. I have experienced that myself a couple of times. And I must say I was on both sides already: the one being bored and also the boring one.
What I did to stop this is the following: Instead of telling people everything about myself right away, I let them ask what they want to know. AND additionally I will reveal them some things as some sort of bonus. You kinda have to pay attention, that you grade all the information about you over a longer time span. This way you won't get bored or boring too fast.
What also helps is, if you have contact thru mails instead of chats, phone or every day communication. Because a mail is like a letter: it takes longer to respond, which won't allow you to give away too much information at once.
I know that sometimes it is quite hard to keep back, but you should give it a shot. It's much cooler because you can discover the other person (or let yourself get discovered) much longer.
Whatever I do, my rule is to not give away everything at once, but to steadily raise the information. =)