Thanks for the thread, smallereveryday, I've not quite finished reading it yet, but wanted to add something that may spur you on and congratulate you on your efforts so far.
I've been where you are as I had a gastric bypass in 2012.
Sounds like we were similar weights (at my heaviest I weighed 250-255lbs), though my bmi was 46 as I'm a bit shorter than you.
I also had multiple co-morbidities including sleep apnea.
Although it hasn't been an easy ride and there are some things I'll never be able to eat or enjoy again, I don't regret what I've done.
I was told I would likely die if I didn't do something soon and, although I still hate the way I look due to masses of excess skin, I'm still here and no longer suffer from several of my other health issues, including the sleep apnea.
Some of the effects, like sugar dump, can lessen over time and if you're not strict you can stretch the pouch again so that you're able to eat more, and can then gain weight. According to the dietician I saw before surgery (saw 1 for almost a year) I've damaged my metabolism from so many dangerous, fad diets and would always have to be careful how much I ate. I generally have to keep my daily intake at around 1000 cals, otherwise I gain weight.
My best advice to you is to stay vigilant. I've actually found that although I was a chocoholic previously, I don't enjoy chocolate anymore (still got my Easter egg from last year, and told everyone not to buy chocolate any more for me).
My tastes have changed and I cannot eat pasta, which I used to love. I also cannot eat icecream without being sick, so I've not had that in years. I've learnt to listen to my body and eat slowly.
I was an emotional eater, which is why the bypass was best suited to me, and I have to say that that's the hardest habit to break. I still sometimes struggle, but not to the extent that I did before.
I wish you much luck and joy on this journey. 