Breast feeding FTM gorged breast.. advice on how to get milk out

FTM I had my daughter monday and for the past 3 days my breast have been gorged. My nipples are flat so i have to use a nipple shield to feed her. Bt not much milk will come out. I can feel the milk in my breast its hard. They hurt so bad..and I feel want to breast feed my daughter or pump but the milk will only come out of one breast. When it does it take 30 minuts for 1 oz. ADVICE on how to relieve pain and get the milk out ? PLEASE & THANK YOU...