Totally understand your plight! I HATE cardio workouts, so my endurance is fairly poor. When it comes to dancing, there are a few tips I could see helping...
First, for holding your breath: Try to practice your moves while slowly exhaling as you do it. So, if you're doing a basic invert, as you lift your legs begin to exhale, and when you set your legs on the pole and grip on, you should be reaching the end of your capacity, and you'll need to inhale. This is often a problem with a lot of "macho" weight lifters, too. We feel we get more power by hardening all of our core muscles, thus freezing our lungs and holding our breath! But, I've found I get a lot more power, and I run out of air a lot less, if I exhale through moves. Eventually, you can even start teaching yourself to inhale through moves which expand your core and chest, too!
Next, have you warmed up? This one is surprisingly important! That little "5 minute warm up" or whatever doesn't cut it for me! I notice that by the time I'm in about 20 minutes, I'm huffing and puffing and totally pooped... but after I go and have some water, walk around the pole and do a half-spin or other light things, I am ready to go again. And, not only that, I'm energized and feeling way better than when I started!
Scientifically speaking, that's the point when your cardiovascular system (heart and lungs) catches up to the level of energy and oxygen you're demanding from them, thus introducing enough to your muscles, and allowing you to burn fat for energy! Fat can only be metabolized in the presence of oxygen, so after this point, you're working at a much more efficient level, and that fat will give you all the energy you need to get your dancing done!
And, lastly, have you been taking rest days? You need them not only to repair your muscles, but to get past the time of muscle repair, so you can have all that energy again! If your body is trying to do both, repair your muscles AND work them, I would think it'd get tired!
