@morirach It's so hard! I hear you.
I've had a struggle with weight especially since having my second, but perimenopause plus hormonal birth control, as hormone therapy, is also in the mix for me which is its own fresh hell around metabolism and weight gain (plus fat distribution). I've always been an active person, but realized that my old pre-kid habits just weren't/aren't serving me any longer. Also, I LOVE food (used to love nothing more than spending a whole day cooking some amazing meal), but I can't eat like that any longer.
So yeah, I have had to revamp what I eat pretty extensively. Big emphasis on protein, as others have mentioned; for me, that often looks like chicken, tofu, or salmon bowls (with a grain, beans, and veggies). It might sound bland but if you find some good sauces and dressings, it's great! I also count calories in an app (I use My Fitness Pal, which others have recommended), primarily as a way to stave off mindless eating.
For exercise, I've always been a runner but longer bouts of cardio aren't so effective for staying in shape. I do a lot more strength training now, and incorporate additional Pilates classes plus HIIT into my workouts. Still running, but making that more part of the mix instead of the sole focus.