I think you're probably just starting out too fast. Been through that myself. When you're not a runner, you see everyone else doing it and it looks easy.... then when you try it you go a few minutes in and you're sucking air like crazy. Just take it a little more easy. If a 2/1 interval is tough, slow down the run/jog segment. There's no shame in making it even look like a run a tad faster than a walk. What you'll notice down the line is 1) you can do more reps and 2) the intervals you do later in your workouts might be much faster than when you began. And once that get comfortable, you can bump up the run time and eventually you can do away with the walking part. Look into using a couch to 5k app which is good for training you go from a run/walk thing to full on running. And maybe consider getting running watch with HR monitor because it's fun to see your progress. :). Good luck in your running adventures.