Cathe doesn't really respond to posts in here any more. (Maybe she'll make me eat my words and respond, but I'd be surprised.)
I'll put in my 2¢, but feel free to make decisions that work best for you - ultimately the best workout regimen is one that you know you enjoy and will stick to.
I think kickboxing workouts are great for cardio, and possibly on the very light side of muscle endurance considering it's body weight-only exercise (maybe a little extra weight if you're wearing boxing gloves.)
Kickboxing is not the equivalent of actual resistance training, however. I'm not sure how well it would do at maintaining strength gains for you, for example, if you'd been regularly lifting against resistance (dumbbells, barbells, kettle bells, gym equipment), and then stopped lifting weights entirely and were relying only on kickboxing for your exercise.
I'd recommend continuing to include some resistance training at least once or twice a week, and then using kickboxing for all your cardio if you really enjoy it. A full body resistance workout 2x per week, or you could split and do lower body and then upper body. Again, that's if you want to maintain your strength.
For weight loss, 80% of that comes from what you eat. Take a look at what you're eating and perhaps consider logging your calorie intake on a site like Cronometer.com . It will help you calculate a reasonable calorie deficit for the amount of weight you want to drop.
You can also just try cleaning up your eating, too - that sometimes is enough for people. Avoid high-sugar, high-fat, high-salt processed foods (ie: french fries, cookies, etc.) and you might see some improvements there to start.
Good luck. I'm sure some others may chime in with some more suggestions.