Help!! Dress is tight but still zips. Will good shapewear fix this?

We’re exactly 2 months out from my wedding day. I tried on my dress today for the first time in months and was shocked how much tighter it was on me. I’m a pretty small/average size person and my weight *usually* doesn’t fluctuate very much, but I guess I’ve packed on a couple extra pounds over the past few months without realizing it. My dress still zips all the way up, but it is wayyy tighter than it was before and it’s pulling around the zipper. I’m so worried about the zipper breaking! I know I still have some time to eat right, exercise, etc. and if all I need to do is lose 5lbs in the next 2 months I should be okay. But does anyone have tips on how to lose the weight? Also, has anyone had good luck with shapewear making it easier to zip up the dress/prevent pulling? My dress is strapless and the back isn’t low but it’s lower. I’ve attached a picture of the back when I first bought it so you can see what it looks like and LMK of any appropriately styled shapewear I should try!