Breezer, did you really mean to say 198-210 for cadence?

A good cadence for most riding is between 80 and 100 rpm. I usually ride around 90 rpm or so (unless I'm going uphill in which case it's way lower). Shift gears up or down as needed to maintain a good cadence.

Also, if you're out of breath, then I would think your breathing is at its max.

And what are you basing your max heartrate on?