Always struggling for air

I spend most of my day every day trying to get a deep breath and it's becoming exhausting. I've had to quit working out and my job (I'm a personal trainer). It takes all my energy just trying to catch that deep breath, but even when I do it's not a minute or 2 before I need to do it again. Bloodwork came back normal, echocardiagram also normal. Spirometry test during a breathing attack revealed I was only expelling 20% of the air from my lungs that I should be so I was prescribed inhalers. They only exacerbated the problem. They seem to freeze up my breathing muscles. It doesn't feel like my lungs are the problem, it feels like my diaphragm or other involuntary breathing muscles are the culprits. Taking klonopin helps, but I can't exercise on it. Anything that increases my heartrate throws me into a breathing attack where my muscles freeze up. I've had this problem on a small scale most of my life, but it has gotten inifintely worse since I moved to Houston 2 years ago. I should mention that I've been to the emergency room 3 times and each time they tell me my oxygen saturation is 100% and send me home. Can somebody please point me in a direction for help? I know it's not anxiety, though it is aggravated by anxiety, but this happens when I'm sound asleep not dreaming. I will wake up having to take a deep breath and sometimes can only get one in certain weird positions. Please help. If there is a doctor out there your advice is invaluable to me!