1,100 calories daily, and burning off 600 or so of that every other day
Do less. I don't mean eat less, I mean do less. 1,100 calories is not really enough for anyone, let alone for someone 5'9". Some calculations for a female, 5'9" weighing 230lbs (don't know your age so I put in 25, and no bf% guess entered either) estimates a BMR of 1856 (this would be how much you burn just lying in bed being alive) and even sedentary activity level is a TDEE of 2227 (that's with general day to day activity like walking around and sitting upright), so at a 500kcal deficit we're talking 1700kcal and at a 1000kcal deficit we're still talking 1227kcal. On a day that you were burning an extra 600 that means you were burning a total of ~2800kcal and only eating 1100kcal to replenish - no wonder you had hunger pangs and all that jazz. So don't push quite so hard, make it more sustainable. The whole "eating at a deficit that I'm always hungry" is why so many people fail diets - they try too hard, they're hungry and miserable, they give up.
Self control gets you started, but it's unreasonable to expect yourself to ALWAYS practice self control/willpower, so you need to just make it so dead simple, and a habit, that it's just easier to do it than it is to fall off the wagon.
You say you lost your self control and motivation, but those should be intrinsic, they need to come from inside yourself. You were depressed, you lost a friend, and you started eating in excess - did that in any way make you happier? Did you really feel any better while or after eating that large pizza? I'm suspecting the answer is NO, and that's the thing. From all those years you've convinced yourself that when you are unhappy or sad that eating will make you happy, but it doesn't, it just makes things worse. You have to reprogram your brain and this will take time.
From here I can only suggest what I know helped me - two non-diet/health/fitness books: The Willpower Instinct and Self Compassion (or maybe I liked The Mindful Path to Self-Compassion better, I can't remember which was which now)
I wish you the best. Acknowledging that there is a problem and having an awareness of it are the first and most important steps.
We seem to be very similar. For me, there's a thick lifelong layer of depression and anxiety blanketing everything. If that also applies to you, please find help, however small. And don't concern yourself with doing your best or being "normal" right now.
Kristin Neff's books have helped me immensely. I'm not a huge reader much of the time so I listen to her audiobooks when my mind won't settle enough to really read. This is a wonderful one start with.
Self-Compassion by Kristin Neff on Audible
Self-Compassion by Kristin Neff, softcover, Amazon
Self-Compassion by Kristin Neff free to read on Kindle
Dr Neff is behind the website linked by another commenter and it's a very good resource. Browse it as much or as little, as quickly or as slowly as you need to, for you. Check out her books, or look for more free resources. No one is looking over your shoulder. No one is judging you. It doesn't matter how fast or how slow you read, learn, or do anything that benefits you. Life and knowledge are not a competition and you don't owe anyone anything or any explanation. Your growth is yours.
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I agree with a lot of the OP recommendations and didn't want to dupe too many.