This was interesting to me as I have a friend who often over shares, I on the other hand am often described as circumspect.

What I would like to say is that it won't necessarily run people off, I still like my friend, but for me it can be exhausting sometimes it's quite full on. On the other hand some people it may chase off, I'm inclined to agree with mote that maybe those people weren't right for you.

A couple of things that may or may not be helpful. Try experimenting with listening, not just hearing, but really listening hard to the other person, be curious about them, being a better listener is something many of us could benefit from.

Also how about making a goal of the conversation to keep it on fun topics, obviously not always, but certainly at first, so maybe music, film, sport etc, safe topics you can't over share on.

Lastly, I think it's good you recognise it in yourself, maybe if you feel it is safe to do so you could confide in the other person "Excuse me, I tend to over share sometimes " if you catch yourself doing it. My friend does this and it is helpful for us both.

Good luck!