I've been there OP and I did make it over that hump. I had a really unhealthy relationship with food for years and had a lot of weight issues that stemmed from my emotional eating.
It all really comes down to forcing yourself to make small lifestyle changes until they become long-term habits. It took you years to get to this point and it's okay if it takes you years to get to where you want to be. There's no miracle diet or weight loss plan that's going to change your mindset overnight, but choosing to make small changes that impact your life over time will.
For starters, drink more water! Our bodies need about a gallon of water every day and you'll be surprised to see what an impact it can make on your metabolism, your appetite and your overall energy levels to be properly hydrated. I use a generic water tracking app on my phone to give my hourly reminders to drink a glass of water.
For your diet, again, start by making small changes. Even if you aren't eating healthy meals, start by cutting out or down on snacking. Ideally you want to try to achieve a 1500 calorie diet to create a deficit and lose weight. If you start counting calories you'll quickly see how much of your daily allotment is taken up by junk food, sugary drinks, etc. I personally use the www.myfitnesspal.com/ app to keep track of my own calories.
As for exercise, I found a lot of success with Beachbody's workouts. I think their 21 Day Fix program is great for people struggling to get over that hump because it covers both diet and exercise: www.beachbody.com/product/fitness_programs/21-day-fix-simple-fitness-eating.do
If you're interested in checking out some of the meal stuff they have a great section on their blog that should be able to answer your follow up questions: www.beachbodyondemand.com/blog/21-day-fix-hub
Honestly though, there's a saying that goes"abs are made in the kitchen" and it couldn't be more true. No amount of exercise can outdo a bad diet, so start there. Try to cut back on junk, drink more water and just be minimally more active. If you can keep that up for a week, challenge yourself a little more. Set clear, obtainable goals and keep working toward them. That's really the best advice I have for you.