Hey! Congrats on baby and wedding!
Firstly, size is irrelevant. You will be glowing and fabulous whatever happens!
I would say that bf is the ultimate diet. You should be burning tons of calories, and this will take th weight off plus some, even after you stop. So right now, you’re already doing the best thing. We gain weight in order to feed baby! It’s a good thing. So don’t get hung up on it.
Second, don’t try fad diets whilst feeding. It’s important to keep up a healthy diet right now.
If you’re bothered, switch up some snacks for healthy options. Curb the bread and biscuits. That sort of thing.
It might be unrealistic (and possibly unhealthy) to expect to drop several sizes by dieting in a short time. So maybe start doing more walking and swimming. Like really, really long walks a few times a week. If you start now, you will see and feel the benefits.
Do you have a dress already? If not, maybe look for a size 16 that you could have taken it or let out a little closer to the time.
Weddings are stressful, so even without dieting, you may find you slim down a bit in the last few weeks just with all the running around.
Whatever happens, remember your body has just done an amazing thing. It is beautiful, even if there is a little more of it now!