I am 34 weeks pregnant with my 3rd bub and I wa...

I am 34 weeks pregnant with my 3rd bub and I want to breast feed for as long as possible.... With both of my other children my milk supply was non existent by about week 4, with my daughter I ended up back in hospital and on a strong antibiotic to stop an infection in my uterus (I was not allowed to breast feed while on them which meant my milk supply just disappeared, tried to express while on them but it didn't help) with my son I never seemed to make enough and by week 4 my doctor suggested I mix feed because he wasn't putting on weight and she feared he may have been going hungry.... All in all I am completely confused as to how to resolve my problem, I want so bad to be able to breast feed properly and as far as reading books goes I have read a whole load of them and each one differs from the last, it just confuses and upsets me more :( I would love to hear from mums who may have had a similar problem or anyone who knows what are good ways to keep up milk supply etc. Please, any help will be greatly appreciated!! Thank you in advance, Emily