Hi there, you're doing great, I wished I had discovered the babywhisperer when my ds was that age!
If your lo is too sleepy to feed try rubbing the palms of their hands or waking 15mins later to catch a less heavy bit of the sleep cycle.
I personally prefer giving a bf rather than ebm at this feed as I love the closeness.
Sorry if I can't be of more help, at 5wks many babies dont sleep right through the night yet!
Just to clarify... a dreamfeed is where you lift your baby at about 10pm without lights or waking them and, stroking their bottom lip to get the sucking reflex going, feed them in their sleep and then just put them down again. It gives them enough calories to see them through more of the night.