hi nic, jack went through the same thing when he was matthew's age. would take a bottle fine, then one day it was as if he 'forgot' how to drink from one and refused it. after trying different teats, a sipper cup, feeding from other people one day he just took it again..from me.
i think it lasted a couple of months.
i'm sorry i'm not really any help at all!! hopefully some of the other ladies will have some words of wisdom...hang in there!