Why is the exercise getting harder?

Today, I had a meltdown in the car after Zumba class. I've been taking Zumba once a week for a couple months and I enjoy it. The music and the steps make me feel like I'm on vacation. The fact that I like it doesn't mean that I'm any good at it. In fact, it seems as though I'm getting worse instead of better.

A pain in my right hip that has plagued me off and on over the years decided to show up again about 10 days ago while I was in Zumba class. It was so strong that I had to skip the last 15 minutes of class. Today was my first class since that incident and I thought the pain was gone. This was my first class on a Wednesday, so I had never worked with the Wednesday instructor. At first I was happy because she seemed to go at a slightly slower pace than the other two instructors at the Y -- not exactly senior citizen Zumba, but I was able to catch my breath. Then, the hip pain showed up again. I stumbled along as best I could, but I was a mess. When I caught a glimpse of myself in the mirror, I looked like I was about to pass out. This assessment was confirmed at the end of the 60-minute class when the other ladies asked me if I was OK and assured me that it gets better after the first time. I was so embarrassed! I've done Zumba at the Y at least six times, plus a couple times with videos at home.

I managed to keep my emotions in check while I waited for ABM to finish his workout, but I fell apart as soon as we got in the car. I was bawling full-on, which I rarely do in front of ABM because crying women annoy him (it comes from managing lots of women at work; he feels like he is being manipulated). To his credit, he did his best to reassure me that exercising is tough for him, too, and that it will get better. Then he drove by a walking trail that he discovered and mentioned that we could go walking there together when the weather warms up. After years of trying to get me to be more active, ABM is surprised that I have stuck with it for this long, and he may be afraid after this outburst that I am going to give up.

My expectations aren't that unrealistic. I don't put a lot of emphasis on my measurements or the number on the scale. I'm also not expecting to turn into an athlete overnight, or ever. What I was hoping for was to get better at exercising as I went along. The classes haven't gotten any longer, yet I'm having a tougher time getting through them and I am still sore after every Zumba session. What makes the lack of improvement even more frustrating is that I like Zumba. If it was the treadmill I was having a problem with, I wouldn't care. Zumba is sexy and fun and I want to look as good as the instructors do when I do it. I want my husband to pass by the classroom and be proud that he is married to such a vibrant woman instead of embarrassed that I am flailing around and gasping for air. Right now, it feels as though I will never get there.