...but apparently you have also discovered how easy it is to slip back into old habits. Good to see you are back at it big time. No need to mention setting and achieving goals; you obviously know how to do that very well.
You are currently running infinitely more than I am, because I am no longer doing any running.
I was a mile and distance runner in high school and continued running well into my adult life. However, running can be hard on your knees and mine are worn out from all the old karate injuries. Karate was also an excellent fitness activity from which I had to retire a year or so ago - knees again. I am older than you and I now have to be content with treadmill walking with elevation cranked in. (I can't get my heart rate up in my aerobic range just walking level.)
A couple of suggestions if I might: First, don't neglect at least light weight work if you can manage it unless that is already a feature of your regular job. (Maybe you are doing this already; you didn't mention it.) Weight work keeps all of our muscles and bones strong (absolutely essential as we grow older) and hard work is one of the only things that causes your bodies to manufacture High Density Lipoproteins (HDL's - the "good cholesterol"
so it is excellent for your heart as well. (You will get some of that benefit from running as much as you do, but not as much as with weight work.)
Second, after you achiever your weight reduction goals, you might want to also branch out into other forms of exercise activities that you really enjoy. If you really enjoy running, its fine if that is you only aerobic activity (if you don't believe you are damaging your knees). However, if you are not one of those people who absolutely loves running, it can get old and sometimes leads to "falling off of the wagon" as you put it. Diversifying you aerobic activity and throwing in some weight work might help you stay on track.
I hope that you don't view the above a "preaching"; I just like sharing what I have learned the hard way over the many years. If you find my suggestions useful, well and good, but if not, please feel free to disregard them because aside from the information you have furnished, I'm only guessing.