Girl, don't let your Mom make you feel bullied. That was a rude & repulsive comment on her part & if she's unhappy in her life, she should NOT take it out on you. Put that behind you, keep your mind focused on where you want to be, & know that on your wedding day, you will feel & be beautiful whether you're 50 lbs. heavier OR lighter! Congrats on your engagement!
When I went shopping for my wedding dress 7 years ago, I got so upset seeing all these dresses that were sized a lot higher than I wore, with way too much fabric trying to *hide* my fat...they just weren't me at all. My last place I went to was David's Bridal, where the dress I'd been drooling over since before I got engaged was. The only size they had was a size 20, I said screw it, I'm going to at least see what it would have looked like on me...and the dang dress fit & we all knew that I was wearing the dress I'd go down the aisle in!
It was strapless which then, most plus sized dresses aimed to cover up with sleeves/lace/etc., but dang it, even if I have a little bit of back fat in a couple of pictures, I still felt like a princess.