Hi,

Can you tell me, do you have a family history of eczema or asthma? Either side of the family? 5 weeks is very young to have eczema What does you MIL think?
I know it's hard, but I would try to lose the dummy for a while. Try some extra feeds during the day - if he's grizzly give extra feeds in preference to the dummy.
I will try to find you an LC in your area