I can understand that, interviews can be crushing sometimes. Aside from my ability to be flawless for 10-15 minutes straight (force of will + bag of tricks), they can be tough to do. One of my tricks, specifically for phone interviews, is to write out my background (because they're going to ask) in such a way that 100% of the wordage I can do without issue. Mechanical Engineering? That's cool, I worked with them a lot while at the engineering firm (I was doing electrical work). I hope you find a place that fits well. I know the mech engineers at my place had to talk on the phone constantly, just as much as I used to (which landed me in that unpleasant circumstance..). That 3 seconds or less, is that with everything or just after someone asks you a question? Ever tried talking as low as you possible can and see if you still stammer? Changing the tone of my voice is one of my tricks to speak flawlessly for a bit. If you talk as low as you can (near the point of hurting), and it works (read something, even this outloud), then adjust your tone a few notches to bring it back near normal levels, but not the normal level.