I can't keep motivated

You should probably enlist the help of a mental healthcare professional if you haven't already, they can give you much better tools to manage binge eating than random Internet strangers can. If your job has an employee assistance program (EAP), you might even be able to get a few free sessions (usually around 6-7 in my experience).

Take a week or two to honestly log what you eat normally - get a sense of how you actually do eat, before you get all wrapped up in ideas about how you should eat. Ideally you would weigh everything to get more accurate data at this stage, but you can take the first week to get in the habit of logging at all before you add in building the habit of weighing your food first. If it will upset your brain-weasels to see a big red number at the top of your diary and you can't ignore it easily, manually reset your calorie goal to something wild like 60,000 calories per day, something you can't possibly go over. (Go to Home > Goals > Edit on the desktop site, hamburger menu > Goals > Calorie, Carbs, Protein and Fat Goals under Nutrition Goals on the Android app.)

Once you have data about how you actually do eat, you should be able to identify one or two easy changes you could make to reduce the number of calories you consume in a day. Just for one possible example, if you drink coffee with creamer and sugar, you can probably use a bit less of those things and shave off a few calories that way. Give yourself time to get used to whatever you decide to change, then once that's second nature, find another easy change and focus on that for a week or two. This is a marathon, not a sprint.

This is probably my 15th run at the whole weight-loss process in as many years, and my thinking this time around is this: when I get to goal weight, I will still need to eat food, and it will still have calories. So, in the process of becoming a person who weighs X lbs, I need to learn how to eat like someone who weighs X lbs. If I treat the changes and choices I make now as temporary things in service of a goal, what happens when I get there? I go back to living my life the way I was before? That will get me right back to where I started. No, these changes I'm making need to be permanent and sustainable, which means slow and steady and one at a time, for me. The routine and behaviors of "log food," "weigh food for accurate logging," and "choose food with the goal of consuming fewer than X calories in a day" are three different habits that I've cultivated one at a time, roughly in that order. Maybe someone out there has been successful with just discarding all aspects of their Life as a Fat Person, emptying their fridge and refilling it with all new foods and starting over Day 1 with a whole new routine from scratch, but that sounds exhausting just to think about.