As u/davidofmidnight said, make sure you discuss this with a medical professional first.
Now with that disclaimer out of the way, in my experience to my early IF days, the most surefire way to trigger a binge is when you just jump into not-eating and/or try to stretch the fasting time to get quick results.
With the diabetes and previous eating disorder history I would say that there is no way to give you advice or even suggestions that would be certain to work for you.
In your position I probably would try to proceed gingerly and with much caution and start with a less radical fasting schedule, if for nothing else to make sure that I don’t end up triggering another binge.
Maybe a 16/8.
It would also provide your body to get used to a new schedule and come off from the “food-on-demand” mechanicsm.
When you are past maybe 3 weeks of it and everything is stable, you could go for the extending of the fasted state to 18/6.
In those weeks you could check what is your usual calorie intake with brutal honesty toward yourself, calculate a daily average intake and carve a little off the top.
When that is done, you can look up ingredients that agree with your body, have a low(er) calorie amount but high volume so you still feel satisfied and well fed enough while cutting back on calories.
The combined effect of your body having less calories to work with and no longer having food on demand will start to make it adjust and start accessing stored energy and break down fat.
If you will do measurements, keep in mind that meals with high carb content will give you water retention that can look like sudden weight gain so don’t panic, just look at what you ate beforehand.
I also don’t know if you use added sugars in your drinks/meals, but transitioning to sweeteners will also result with more available calories in your meals and fewer up and down swings in your days in terms of how much energy you have. (this does not mean completely abandoning things that naturally have sugar in them or such, just drinking tea with artificial sweetener instead of sugar, or using 2in1 - creamer and coffee - with sweetener, instead of 3in1 that had added sugar)
Again: discuss the plan with a doctor, because they know better how it would effect the issues you deal with, or if it is even safe to proceed with.
With that being said: Welcome to the IF Crew and I wish you success! ;)