Hi, I'm a BGF, or maybe that's ex-BGF or former BGF, as I'm no longer with my BF anymore. But something about your post reminded me of my own body insecurities. My body has changed dramatically over the course of my 2+ yr relationship, mostly to no fault of my own. I have had some similar body changes to you, but without the joy of saying I birthed and fed children. If anything, my body changes are actually directly tied to my inability to have children.
In the 2+ yrs we were together (which includes a 7mo break in the middle), we were only sexually active for 3 of the first 4 months. He would give me compliments that I looked good or cute, including when I was in a state of undress or half undressed/lingerie. Then...things fizzled off. It was mostly him being aloof, and me going with the flow because I was a pushover and also because I didn't prioritize sex enough to insist on it, as I prioritized trying to prove myself to be a good girl suitable for marriage more than anything at that time. Looking back, I wonder if that's when he started straying, during the 6-7mos that we were still together, and still sleeping next to each other and stuff during sleepovers, but not having intercourse. He was more aloof about complimenting me, similar to how that geek Sheldon from Big Bang Theory would be towards his GF, prior to actually becoming sexually active with her. (That scene where Sheldon's GF Amy is laying across the sofa seductively, dressed as Snow White trying to get his attention while he pretty much ignores her to work on his computer, is always a trigger. And no, my XBF was NOT the nerdy asexual geek type either, which probably makes his aloofness towards me even worse!) During our 6-7mos of celibacy, he became more aloof, complimented me less, and I started putting on unexplained weight and abdominal swelling. I even mistakenly thought I was pregnant at one point.
After 10mos together--including 6-7mos of celibacy--he abruptly dumped me, a total surprise to me. We were apart for 7mos. During those 7mos, my physical health went to hell: I gained much much more weight, had severe leg swelling and blatant varicose veins pop up everywhere, and I began to look around 6mos pregnant despite my lack of sex and obvious lack of a baby. Turns out I had rapidly growing uterine fibroids and cysts. That's why my uterus expanded as big as a pregnant woman's. The fibroids were also one of the causes of my infertility; I'm told it's not impossible for me to get pregnant, but definitely difficult and would likely require expensive IVF with no promise it'd work. I ended up having to get them surgically cut out with a very invasive, complicated, life-threatening myomectomy. I was put on bedrest and restricted from exercise before and after this surgery. I am also on birth control to control the fibroids, making me further infertile. As a result, I now have a surgical scar similar to a C-section but 3x wider, extending from hip to hip. This incision, along with the abdominal swelling and then fibroid removal, has resulted in my belly being pouchy and sagging over my incision, similar to what apparently happens to some women after a C-section. Actually, it seems like everything has gotten kind of saggy. I've lost weight since the surgery and medications but not nearly fast enough. I still weigh more now than I did even 1yr ago, although a good bit less than I did right before hospitalization and surgery.
When we reconciled, I must say XBF did not seem impressed with my different body. Preemptively I
was almost ashamed to let him see the scars and veins. I was afraid what he might think or say. My insecurities seemed confirmed especially after his immature friend made some rude comments, asking me if I had C-section scars and stretch marks after I told him and a few others that I'd just had a myomectomy surgery. When his friend said that, my XBF actually said to his friend, "Geez, stop, I find varicose veins and scars to be absolutely disgusting." I definitely felt ashamed of my body after that, even though he hadn't even seen me naked in many months, before our 7mo breakup. His continued lack of sex, even after me finally summoning the courage to make a move indicating my desire for sex, had me feeling even more horrible. Unfortunately, this continued and I never had sex with him ever again. I have now reached a whopping nearly 2yrs with no sex.
My XBF hasn't admitted much about his infidelities, and the only thing he's admitted to, he claims was a rebound not an affair, that just so happened to occur right after he dumped me. Yeah right. Anyway, that girl has 2 kids but apparently doesn't have an obvious "mommy body" if my XBF didn't think she had kids until she told him afterwards. That realization has me feeling more insecure than ever. Knowing that even a girl who actually HAS kids, has a better body than me. I'm sure my XBF probably thought about me, "She wants kids so badly but if she looks this sloppy before she's even gotten pregnant, imagine how badly she'll let herself go once she has a kid." Okay that's my speculation but still.
OP, on the bright side, at least you have kids to excuse any self-perceived flaws. At least you have that badge of honor. Your H has to respect you for that, especially since they're HIS children you bore. Some of us have body insecurities and don't even have kids to show for it.