The classes are a really good way to raise your heart rate and undergo a solid cardiovascular workout. Make sure that you continue to increase the intensity each session as you become fitter.
Thing is, you need to continually push your body outside of it's comfort zone in order for it to respond. I wrote an article entitled "The Art of Adaptation" which I would highly recommend you read if you are seeking to improve your fitness. You may feel sluggish now, but if you remain consistent in "pushing" yourself, you will soon notice a significant improvement in your level of fitness.
To improve your fitness and assist in your goal of weight loss, you do need to ensure that your nutrition is adequate to support recovery from workouts in addition to weight loss.
Finally, to assist in reducing your "love handles", you need to focus on weight loss, which will be a function of calorie expenditure and nutritional intake. There are no exercises that can specifically target this area on your body for fat loss. Such a myth is termed "spot reduction". I'd recommend you read a course I published on weight loss here.
All the best!