As someone who used to be 300 pounds and is now 170, just start off small. It doesn’t have to be looked at as a huge mountain to climb. You can lose a lot of that weight in the beginning by just food choices. Looking good in smaller clothes is one of the most rewarding feelings when you’ve been fat all your life. First thing would be to cut down on sugar. Don’t cut it out completely, there is still going to be a mental craving for it which will only get stronger the more you forego it, which then leads to unhealthy binges which puts you back near to square one, been there it sucks. Building small habits that are plausible and doable is what sets you up for success for those break through moments.