Breast feeding problem. Shipeds then?

I have a one week old newborn but the prob is in the lst two three days he was sucking nipples but later on he is unable to also I have inverted nipples, so pumping and expressing milk now as have already got milk, using nipple puller but when the baby is sucking it is going back to its old position, baby trying to suck am trying to latch but not successful. Please help how can I breastfeed him, I cannot just rely on pumping kipkyfor 6 months, after some days when he is a bit matured can he suck or breastfeed then? Or should I use a nipple shield atleast he can breast feed. Also improper drainage of milk can cause infection in my breasts, please doc plz advice whether to use nipple shipeds then? I heard it is not good but also as he is not feeding