I'm so done!

Roxanne • Pregnant with baby 5, due June :)
My little boy is a week old today. I've struggled with expressing because he won't latch. His only having formula once or twice to top up and I really thought I was doing ok. I've just had a breast feeding advice lady come round and all she kept saying was how important it was to get him to feed off of the breast. She says that the milk won't change to keep up with his growth and that expressed milk is not the same. I have 4 other children and time is limited as it is. She's made me feel awful and like after all the hard work I've put in it's still not good enough. I really think I've had enough.  When you make the decision to stop breast feeding what the best way to get your milk to stop ect?