I am the classic overtalker. Meaning, I have a habit of sharing too much of my opinion in social situations and then realizing I've totally offended at least one person in the group. Sometimes I don't even really agree with what I've said myself!
Sounds like you might be a bit of a nervous talker....am I right? Filling silence, compelling yourself to carry (aka control) the conversation. Trust me, there are worse things to be, so don't be too hard on yourself and let's start with some strategies to help you feel more comfortable in social situations.
I have a friend who is lovely and bubbly and often the life of the party. She flits about from group to group and laughter follows her wherever she goes. She claims her secret is in the "listening to talking ratio." She warmly greets, brings up a topic that is complimentary and lighthearted, and then tells herself keeps her responses to a sentence or less for the first 50% of the conversation. If it's a group of 4 or more, she bumps up her listening time accordingly.
Listening is key. It may feel strange at first, but it is not your responsibility nor is it polite to dominate every conversation. Plus, the best part of conversation is learning what others have to say! If you get nervous, ask questions rather than issue statements. Occupy your mouth with a warm smile, laugh, nod your head, make eye contact. By doing these things, you will instantly relax the other guest and let yourself relax into witty clips and warm exchanges.
If you ever do stray and say something you regret later, honest and direct is best. If you truly don't agree with what you said, just explain that you were nervous, got a little carried away, and that you are truly sorry. Though, if you follow these guidelines, you'll start noticing that you need to do less apologizing and more RSVP'ing....
(photo: Marilyn Monroe via Dr. Macro)