I'm an attorney with a similar problem. I think it is the bipolar, because I have worked and worked on this and I find that my speech continues to be more forced than most people's. I have found that meditation has given me the most help. Learning to sit through thoughts and emotions without doing or saying anything is good practice and can actually be learned. I've had to start slowly, 2-5 minutes at a time. But it does help me.
Be good to yourself. And I agree, humor does help diffuse situations where the cat is already out of the bag. Best of luck to you!