I was obese as a child/ teen and started restricting the summer before my junior year. (I was starting a new school) And a very unhealthy, addictive pattern of starving (sometimes no more than a few saltines a day) and binging was born. My weight has yo-yoed between the same 30 pounds for almost 15 years. Once or twice I looked for help for the binging, but secretly I wanted to perfect the starving because that's when I was thinner.
Last year I finally commited to heal from all disordered eating, and I'm no where near done. I, like you, consider myself a very disaplined person. (I'm a runner too BTW

) Binging seems so out of character for me as well.
Here's what I have learned:
To stop binging, you need to stop restricting. This was / is the HARDEST part. If I binge, restricting the next day "purges" some of the guilt and anxiety that goes with the binge. It took me almost a year of learning to go back to a normal calorie amount after a binge.
Stop exercising to "purge" a binge. I use the word purge because I personally don't purge the typical way, but purging is about relieving the anxiety and guilt (This is the real pyscho babble of eating disorders and I've found for me it rings true) I had to make my exercising about the exercise, NOT something to cancel out binge calories. So I started running. I felt like I had no goals at the gym, and it was always about weight loss. With running, my goals are about time, distance, races and whatnot. Running is its own hobby. I run if I binge. I run if I don't.
I used a Eating disorder App on my iPhone, called Recovery Record. Its great. That was my diary. It helped me really see the where why when and feeling of a binge. I recommend it.
I treated myself like I would a patient, or a diabetic. I weighted and measured my food (still do) because I do not know how much to eat. I chronically under eat, or over it if left to my own intuition. I've tried intuitive eating many times. And either the crave to binge takes over and I eat way to much; or the guilt takes over and I don't eat enough. I remind myself that I am sick even though no one can see it, and only I am responsible for my recovery.
I am careful to pair a protien with every meal/snack, even if that means a few almonds. I do not eat fruit or sugary items without a protien. Even ice cream, when I have some, I put walnuts on it. I have learned that a sugary food (banana) will lead to a binge on it own. Most likely from the fact that sugar foods (fruit or candy) lead to a spike in blodd sugar then a drop. A slower digesting protien or healthy fat helps to keep blood sugar more even. I found this helps me tremendously.
I eat 6 small meals. This has help SOOOO much!!! This is my main action that keeps most binging away. My breakfast, lunch and dinner are small - medium, and I have a mid moring snack, mid after noon, and after dinner. I eat between 1300-1500 cals a day.
I eat when I'm not hungry if its my snack time, and keep the snack small. Sound counter productive, but really it helps me stay on track the next meal. This also means I eat MORE during the first half of the day. My personal binge/starve pattern is that I barely eat all morning, and early after noon, then go crazy in the evening. Making sure I eat enough all day really helps. So I'm not allowed to "cheat" by having a 100 calorie breakfast and a 600 cal dinner, or "save" calories for a binge. I've tried that, and it leads to failure for me.
I've ideantified my "danger times", For me the first one comes up around 3p-5p. This is when I start grazing and it can easily turn into binging. I try to have my after noon snack around 2:30p-3p, before the need hits. If I'm still looking for food, say at like 4pm, I have dinner early. Waiting until the set dinner time, leads me to a binge at dinner. After dinner is rough time for me too. I plan a snack.
I don't make any foods off limits. BUT I keep binge trigger foods out of the house as best I can (I live with my husband and kids). I buy one portion, if I want it. (I buy single serving of ice cream, the tiny cups, because if I get a pint or half gallon, I will eat it all. In one night.
I've started therapy to help figure out the underlying issue that might be at play here.
I hope this has helped. I found that I needed to change my mind set to treating myself as a recovering patient to really make progress. When I was still caught up in the weight loss I wasn't able to break free from the cycle. Don't get me wrong, I want to lose this weight, but for now I've set a very slow weight loss goal, so I can focus more on my recovery rather than losing weight.