Hi Jellybean.
Congrats on kicking the purge part. It's one step of a very long journey! The fact that you're here means that you have the willpower to lose the weight. We're here to help keep you on track.
I know it's super-hard.
I know that all of us have been at this point during our journey.
First thing-- is there a reason why you're choosing not to use a binge-eating diary? It's your choice not to keep one, but I find mine invaluable. It lets me know when I ate, how I was feeling at the time, what I ate, how I felt afterwards and what was going on at home/school during the time and I'm able to identify the triggers for me (usually boredom, but occasionally it's when I feel most vulnerable and lonely). Most people don't like looking back on bad behaviour; it's a form of self-criticism (if only I'd done that, if only, if only!) and lots of people can't take criticism. It's not a failing, it's a fact.
You mentioned a writing course. Cool! I'm a writer too- working on my first novel. I suppose part of what you're working on is peer feedback or critiques? If you can get work with the critique someone gives you when you write, do you think you can use the same critique methods to help you stop bingeing? Not put-downs- never those! But honest constructive criticism (I did really well doing "X"; I liked "A" and "B" because of "C", but it would be better if "Y". This form of feedback already presupposes that you've done well and what you can do to make it better).
There is a fine line between ED and healthy eating and it is hard to figure out where it is sometimes. A healthy dieting regime is eating healthy food with the occasional treat. I think where most people fall down is that they cut out treats completely- no more chips, no more chocolate, can't have lollies, can't go out for dinner, must avoid bread, must avoid dairy, etc. It's a load of bullsh!t because the more you avoid it, the more you want it and when we get it, we binge, we feel like sh!t, and we binge again because we feel like sh!t.
Getting back to the healthy diet vs ED. Firstly, know that a healthy diet *is* the only way to lose weight. Exercise will help. 80% of the weight we lose is through good food choices; the other 20% is through exercise. In order to keep the weight off, you need to commit to both. ED can only hurt your attempts. Without trying to lecture you on WHAT to eat, I can only guide you on how to eat. Whether you take up the guide is up to you.
Firstly, never throw out all the snack food. Keep some of it. It may sound counterproductive, but some times we WANT that chocolate chip cookie. Don't have 15, have 3. But before you do, ask yourself "How am I feeling? Will I want this in 10 minutes? Will something else (crunchy, sweet, gooey) fill this craving?". Most of the time we eat to fill a void- boredom, emotional, social or psychological, even spiritual. As a writer, I use writing as an outlet for my cravings. Sometimes it works, sometimes not (like yesterday!).
Second, try to include 5+ fruits/veg a day (2:3 or 1:4 ratio). You can easily fit these in. A piece of fruit at breakfast, or a grilled tomato on toast; 1 down. 2 cups of salad at lunch; 3 down. A cup and a half of fresh veg for dinner; 5 down. That's actually "more" than 5, it's more like 7, but you get the picture.
Third, allow yourself to make mistakes. We are human and we make mistakes. Get up (mentally) and brush the dust off. Tell yourself "it's okay; I can still get back on track today."
Lastly, if you're worried about the "justifying 'that little treat' when I've already had 5 'little treats' that day", then this is where your willpower and self-discipline needs to kick in. Again, the best thing to ask yourself is "will I want this in 10 minutes?" Invest in a timer or use the timer from the stove or microwave. Set it to 15 minutes, then do something else to keep you occupied. Most of the time, you'll find that you will miss hearing the "ding".
This is all I can offer you except that if you need to, post here. Someone will always read what you have to say.
Here's another
Out of control
I'm going to get going again. We have a WiiFit Balance Board (son just hooked it back up), and having an animated piece of plastic tell me I'm "obese" every day is a great motivator! 
