A few thoughts that might be helpful:
Why don't you read more OP? Reading has a tendency to quiet me, and it gives me a legitimate thing to discuss with coworkers and friends.
Volunteering and hobbies can also help.
Don't feel so self-conscious, if you have this level of self-awareness you're probably a great person. Just own that and work on having interesting things to discuss.
Also, meditation is great. There's a lot you get out of yourself and other people when you practice quiet. Quiet can be really fulfilling when you own it.
Another great exercise is to ask someone about themselves - in a way they wouldn't normally expect to be asked about, and then just sit back and listen. You learn so much, and people tend to adore you. "What's your favorite vacation ever? I've been thinking of traveling."
Travel!
Best of luck to you OP. You're just fine, and I'm surrounded by people/ DH, animals, kids, constantly surrounded, and I still talk too much (to myself sometimes too