Weddingbee boards

When I bought my dress I was not planning to wear anything underneath it.  It fit perfectly, has a "built in" bra and I felt fine in it.  Well I've gained about 10-15 lbs since then and now I feel self conscious in it.  Here are some pics of when I bought it and what it looks like now.  The corset was not tied very tight in the recent pic, so hopefully it will look better tied tighter.  It's also not hemmed so it's pooling on the floor.

Any advice for shapwear that will tuck me in and make my belly look flatter?  I have a large bust (34G) and it obviously needs to be strapless.  There is a lot of boning in the dress so it doesn't really matter how "smooth" the shapewear is.

When I bought the dress:

Now (still unaltered):

You look very pretty and do not look like you've gained weight in the 2nd one. It is very, very flattering on you...I understand about the busty part I wear 36DDD which gets me into larger sizes. I recommend going to Nordstrom if you have one near you.  They have a huge undergarment section, and second to that I would recommend Macy's. Congrats!