If you place your hand on your belly, you should feel a gentle up and down movement as you are breathing in and out. That's the diaphragm. If you relax it, it will move automatically, if you are tense it will stop moving. If your muscles in the throat contract, it feels like someone is strangling you, cutting off your air supply. You can gently place a hand around the front of your neck and feel if you can detect tension. Hold your hand there while you swallow. That shows you what the relaxed versus tense state of your larynx feel like.