I've just had similar experience with my LO now 8 weeks. I think his mouth was wide enough but pretty sure a tongue tie was stopping proper feeding at first. He wasn't gaining weight very fast and had jaundice and I had extremely painful nipples. Felt like razor blades some days and got that lipstick end. He's now doing great with it and I wanted to let you know our story in case it's any help to you.
So this time round I felt more confident as I'd had the same thing with his brother who's now 7. Ended up that neither of them regained their birth weight till 3 weeks and my 7 year old is totally fine btw, one of the tallest in his class etc.
My first DS had a kind of ambiguous tongue tie and it wasn't snipped until 2 weeks. Milk supply (and my head) suffered as a result as I found it too hard to do all the pumping as well. However we persevered and I managed to do combination feeding. He dropped breastfeeding at 8 months and it felt like my supply had never really established properly and was getting less and less, and we kept increasing the bottles. It was still a really rewarding experience however looking back I sort of wonder why I gave myself such a hard time to keep on, as it would have been special anyway.
This time round I think our new LO has got a tongue tie too, certainly felt similar with clicking and coming off etc, but not as bad. Midwives didn't even really want to look cos they couldn't offer any treatment. Anyway, obstinate head kicked in and because of previous experience, and also because my partner was around more, I decided to give it a try and managed to keep the pumping going with bottles to make sure he's gaining weight. Some days I totally sacked it off but I tried to get 1 or 2 pumps in. I decided to be flexible but aim to keep the bottles at 90 ml, giving 4 or 5 bottles a day after breastfeeding. If he was still hungry I tried to eek a bit more from the boobs after the bottle as well. Ouch.
At some point around 3/4 weeks it felt like his latch changed. He woke up a bit, maybe his mouth had grown? At the same time my milk started coming in better, getting the occasional flooding which was exciting for me. He's now feeding well, still has about 4x 90ml bottles which he doesn't always finish, and I think for us it will continue ok. I'm not pumping anymore, I think I stopped around 5 weeks. He's had another growth spurt and he doesn't seem hungry after having a good go on the boobs, so it's looking ok for now. Does take ages to feed though!
Sorry if long winded, just wanted to give you another perspective, and maybe hope to hold on a little longer if you can bear it, but if it's feeling just dreadful then don't, cos everyone's situation is going to be a little different.
Having a mare with naps, wind and night waking now but that's a whole other matter!! Good luck with it whichever route you choose. It's so stressful and you've got the birth to recover from too, plus I guess you've been trying to do all this in the ridiculous heat wave temperatures.
I also had an idea for meeting with the private practitioners. Could you perhaps explain your auditory processing and record the meeting to play back later?
Key things that helped with me:
*Feeding with good upright posture when he'd gone off the latch again to reeducate his mouth. Especially in the day, then I could be a bit more slack at night
*Making the latch quite deep by really pushing his head into the boob so the nipple hits as far back as possible
*Drinking lots of water and eating nuts, avocados, chocolate etc
*Lanolin!
*Making sure he has 2 goes on the boob before moving to the other one
*The shallow lapping can be important part of the feed not it's just nuzzling for comfort as I'd thought, your midwife will be clearer about that
*Feeding him in a nappy to stay awake
*Skin to skin when I could and occasional all day in bed
*Pumping when I could, very important. I learned that the action of pumping for 10 mins each side soon after breastfeeding is stimulating even if not much comes out. Some midwives said unrealistic things about pumping 12 times a day ffs, but i think my top was 4 and usually 1 or 2, these got put into the bottle and made up with formula to get 90ml
- Hot flannel on boobs and the odd bath
*A back rub would have been nice but I don't think I got one.... Hmmph
*Trying to be flexible and not do my own head in
*Repositioning him further round me on one side seemed to help.