My best tip would be to reach out to a lactation consultant - they're trained to help with all of these issues and more, and can offer personalized advice that takes your unique situation into account.
If you're dealing with sore nipples, make sure your baby has a good latch. If your baby isn't latching correctly, it can lead to pain for you and not enough milk for them. Consult a professional to check your baby's latch and adjust if needed - it made a huge difference for me!
Also, pumping can help alleviate some issues. When I was dealing with oversupply, pumping just one session after a feed helped ease engorgement and gave me some control over my supply. It also built up a stash of milk in the freezer, which was an added bonus! But be careful - if you do this, make sure you speak to a lactation consultant first, because improper pumping can encourage oversupply.
Good luck, mama! Hope things get easier soon!