VQ hugs. Would you consider combination feeding? It works for me, but isnt for everyone. If you did, he'd have the benefit of your milk (and you have already given him a fabulous start) and some bottles which might knock him out for longer? Also DH can share the burden etc? You have said before that you wanted to give him the same as you'd given your girls - which is admirable but not necessary. Every baby is different with different needs. Give yourself permission to do what you need to do to cope, not stick to a pre-conceived notion of what you must do because it is fair, even though it is detrimental to your health.
As for co-sleeping - I never intended or wanted to do it, certainly didnt do it with DD when she was a baby. It was GF all the way. Now DS sleeps with me, and DD with DH in the spare/their room. It's not perfect, GF would be horrified, DH and I rarely cuddle or have sex or can see a time when this will happen. However, we are doing what we have to, to survive/cope.
I'm hoping you're right about the scar. May get my sister (who is a doctor, but not a GP or obstetric dr) to have a look. Yet more evidence I need to lose some weight.