I have a 1 week old baby and initially breast feeding was going well. I'm now struggling getting him to latch on and am sore and tired. He is sick alot after feeding and im not sure how much he is taking. I have decided to change to formula milk, do I stop breast feeding altogether or do i gradually introduce the bottle? How do you choose which formula milk to go for? I have a 2 year old but she was on nutraprem on prescription so didnt have to make these choices. Thanks.