Shortness of Breath. Heart related?

Walking to the bathroom makes me breathe hard. I had a Pulmunary Function test that was normal, a cardiolite stress test that was normal, and an echo-cardiogram that showed that the left side of my heart is thicker than it should be, but not enough to be causing my problem. When I first started noticing the problem I tried walking for exercise to improve my stamina but it got worse instead of better. I have type 2 diabetes, sleep apnea (cpap machine), fibromyalgia, arthritis, high blood pressure(controlled by meds), high triglycerides and I have been overweight all of my life with little success at losing weight. I have never smoked and I don't drink more than an occasional Margarita with dinner (1 or 2/month). I am 51 years old, all the kids are grown and out on their own. I haven't worked in over a year. This thickening of the heart muscle has me concerned even though the docs are not. Something is taking my breath. Any ideas?

Could have a weak or infected heart valve that does not close completely on effort.

A stress echo test would show either of these as it did for me.

Have you had your blood checked for anemia?

I also have fibromyalgia, with chronic fatigue syndrome, etc... On my bad days I also get winded from doing next to nothing. Pulmonologist said it is just the breathing muscles being too fatigued to take normal, deep breaths. Only solution is to rest, plus I do better in air conditioning. Hope this helps.