Need help Ladies

Ladies I need y’all help. I have flat nipples, hyena suggested nipple shield I started feeding with nipple shield . I had very low supply but supply increased on left side and decreased on right side . Left side nipple came out due to constant pulling.

When my LO started latching directly milk supply increased tremendously . During night when he sleeps for 4-5 hours . My left breast gets full becomes very hard and my nipples become sore and it hurts badly while feeding, is it normal?? How do I overcome it.

I am not feeding from right side, nipples are still flat and it hurts badly while feeding . My breast never turns full or hard. When I pump I hardly get any milk. Is there any way I can completely dry right side??

Did anybody experience this before ? I need advice . Ladies please help.

I had very difficult pregnancy and now I am 6 weeks PP still struggling