Hi there,
Please don't stress about losing the weight quickly - 9 weeks post birth is not a long time at all! Your body has been through so much in the past year, its important to just take things slow and steady. It sounds like you are doing all the right things, and I don't doubt that you will lose the extra weight, however you need to give yourself a bit more time! Your body may not want to drop the weight at a dramatic rate - due to it needing the stores to breastfeed. But don't stress, I'm sure it will come off over time.
I always found the best type of exercise to help me lose weight was actually resistance/weights, such as pump classes. As they increase your lean muscle mass, which increases your metabolism so you are burning more fat at any time of the day - and also helps you feel great because you are stronger!

But seriously hon, I bet you look beautiful as a new Mummy as you are atm. Please don't stress about it, if you keep up the healthy eating and exercise the weight will definitely come off, it just may take longer than what you thought - and remember, its actually healthier for your body to lose weight at a slower rate than a faster one.

All the best....