Meg I think you are still being TOO ACCOMMODATING.
Big freaking deal you don't respond to his text until the next day - you still respond and you write novels.
I believe your H will end with with OW. I believe that your H does miss and care for you deeply. I do feel that he is classic MLC and I stand by my earlier thoughts that H feels unappreciated by his children - right or wrong those are HIS feelings. Don't invalidate them by telling him he needs to work on his relationship and building better or repairing bridges. A simple yes - teenagers can be self absorbed and ungrateful. He feels he is just a paycheck (... so did my H.)
Meg... dear Meg. You need to give yourself more time and distance from this. You need to stop agreeing to see and meet with him every time he asks. It looks like you are just sitting and waiting on him. Do forget that when he comes around and is even sincere you will get angry with him. You have a lot of undealt with emotions as well. Do you want him back after an A - you still have to figure that out.