First of all, I'm a big believer in going into marriage with both eyes wide open, and that includes exploring each persons approach to life, health, fitness, finances, children, etc. Not being on the same page on any of that is a huge red flag. If somehow all of that stuff changed after marriage, or if it wasn't discussed and then it became a problem after, you can either divorce, live with it or work on it. Berating, shaming, condescending, coercing or otherwise emotionally abusing the other person is unlikely to lead to a happy marriage or a successful resolution to the problem. Taking the right approach matters quite a bit, and the wording of the OP is not inspiring confidence.
My advice would be to immediately stop with the shaming language and trying to force your lifestyle down her throat. It reminds me of the dynamic of my parents marriage, where my dad was sure that he was right and if my mom would just listen to him everything would be fine, but she was just so stubborn and why won't she just do everything his way. Unsurprisingly, this ended in divorce.
Start listening to her on what foods she does like, and make healthier versions. Carbs are not evil, and should be part of a healthy diet, but not overwhelm it. She likes pizza? Make it instead of ordering it, and include veggies on top. She likes cookies? Make cookies at home, and substitute half the flour for whole wheat. Meal prep healthier things that she does like and make them easily accessible so that it's no extra effort to choose the healthier option. No, it isn't as healthy as chicken and kale, but it is an improvement over packaged stuff, and it will gradually habituate her taste buds away from over processed, salty, sugary, oily stuff. So she doesn't like the gym? That's fine, it's not for everyone. Start going for short walks, just to get outside and talk and rebuild your love and trust. Don't talk about her weight or her diet, don't make it stressful, just relax and enjoy being in each other's company.
If you are committed to making this work for your kids and yourselves, you have to stop seeing yourself as the one who knows everything and start listening to her concerns and working with what she is able/willing to do. It won't happen in a day, but the small changes do add up.
Good luck!