I just graduated with BSME degree, and I feel the same way that you do. I'm going back to school for a Masters degree, and I'm so scared of having to present research findings. There's definitely a relationship between how confident I am in the material (how immersed I am) and the likelihood that i'll have a block while speaking about it. This makes me think that after being in a certain field for many years everything would become easier for you. Once the vocabulary is somewhat consistent you'll be able to understand how certain words influence your speech in conversation with your peers. It won't be an easy way to start, but it's the only way.