Faffymum - I am so glad to hear you managed to get some sleep. I know if you are not getting any rest it is hard to keep up milk supply.
My breastfeeding book mentions that there is no proof or evidence that Lactase enzymes help at all. Another opinion on the smorgasbord for you.

I am kind of a firm believer in Probiotics and that is about it. More than one Pead told me that I am wasting my money on those Colic drops...don't know who to listen to?!
From what I have read a Chiropractioner is a good idea. Often after 3 treatments there may be improvement. Don't know if you have someone who can take you to an appointment? I know it must be hard to go to an appointment when you feel just getting out of bed is an achievement.
Some babies like white noise. We have the Babysense womb to world on repeat 24/7.
Have you tried swadling your baby? Some babies love it others not so much.
I think it can be so overwhelming to get advise from different areas and not knowing what to do, who to listen to. In the end you must trust your gut instinct (and perhaps accept it is a bit of trail and error). Both you and hubby were chosen to be the parents to that specific baby for a reason. xx