Insulin resistant with hypothyroidism

I'm 5'5" my current weight is 245. I started at 265 so I've come down but I'm looking for help. I've tried cico, exercise and fasting but I've hit a plateau and just don't know where to go. I'm a snacker nothing like binge but who doesn't love a cookie or chip from time to time. I work mid day hours and when I get home it's 7p.m. or later and I'm not hungry. I do try to have some sorta protein tho be it a shake or a yogurt. Any tips would be appreciated? Thanks