Firstly what an awesome & inspiring BFing journey you had with your DS. I think you sound pretty organised, and having been through it before, you know that even if you do start out having to use a nipple shield that it's not the worst thing in the world, and you can eventually wean off it. I had really cracked nipples with my second, and a gf put me onto some awesome gel pad things from the chemist, that were lifesavers. Wore them in-between feeds under my bra, they were a bit like gel pads that you put into your shoes to stop aching feet. I kept them in the fridge so that they went on cold, super soothing

I'd maybe have a look at some Baby-Led Attachment videos, cos that might help give you some more confidence that babies do have an natural instinct for BFing in the first 12 weeks. The ABA probably has some good info on this as well, if you have a wander around their website.