Losing 37 pounds in 5 months is fantastic. But keep in mind that a person can lose weight fast in the first few months--and that speed in weight loss slows down to seems what seems like a crawl at times--which is a plateau--then it will pick up again and so on, if you're working out hard and eating right. It's important to note that pounds that are lost slowly tend to stay off, versus pounds that are lost too quickly. It's gets slower when you start getting close to your goal weight.
But if you keep it up-you're bound to keep losing weight, maybe a little slower but it's still in the right direction.
It's taken me two years of Jazzerise to lose 15 pounds--and I still have few very resistant pounds to go. If you want you can add some elliptical or some weights and other forms of exercise to work other muscles on top of your Zumba-and that might help with the speed-but it appears to me that you're doing just great.
And remember you've already lost 37 of these.
And you did it in only 5 months. Then ask yourself how long did it take you to become overweight?--to give you some kind of comparison
--and then pat yourself on the back.