Has this talking too much been "identified" as an OCD symptom? (I mean, by your doctor etc). Or, amybe I should ask: Does it feel like an OCD thing to you (like, you feel anxiety if you don't say those things, you feel it's compulsive?)
Because as others have implied, talking too much can be a symptom of many other thigns too. I am especially also thinking of (hypo)mania in bipolar disorder.
Not saying that's what you have, don't worry!!
Just thinking out aloud I guess.