SJ, big hugs, babe.
The thing that strikes me is that you were just so exhausted. That's not your fault, and it is so hard to rest when you go into labour, particularly when you're so far past your EDD.
I think you will definitely be good to go for a VBAC next time round. Like others have suggested, a doula could be the most valuable part of your birthing experience next time. To have them around to offer you support and suggestions for positioning and to make you even more active than you feel like being could well be what makes it happen for you.
I'm not an expert by any means, but I'd also reckon statistically your 2nd labour won't be as long, so you'll be less inclined to go for the interventions (AROM, drip, epi, etc) and more inclined to just roll with it.
IRT the pushing - I think it's really odd that you were told not to. I have read that the natural urge to bear down is really valuable in childbirth regardless of how dilated your cervix is. Perhaps the pushing your body wanted to do could've helped Grace to move further down? If she was so far away from your cervix according to your OB I really don't see what harm bearing down could've done to you, KWIM? I have read that damage occurs to the cervix when women are instructed to push against their natural urges.
I think I was probably at about 8cm when I felt the urge to push with Natty. I was sitting on the toilet (not weeing or anything, lol! It was just a comfy place to sit) and I felt two really intense urges to bear down, which I did. Ain't no one who could've stopped me! And there was this gush of fluid into the toilet and I felt her move further down into my pelvis. I think you were let down by being told not to push when you felt you needed to.
I'm not sure how much help this has been - it's all just my thoughts and I'm not medically trained. But I want to reassure you that there should be nothing stopping you from going for your VBAC next time. I honestly believe that with the right support you can birth vaginally if that's what you want.