Congratulations! Keep in mind the power of those hormonally induced emotional swings. You're in the middle of it now. You need time to recover from the C-Section physically too. It can be overwhelming. The Oxycodone will probably diminish your milk flow, make you constipated and can irritate your stomach (it is codeine based); but one thing I remember very well is to KEEP ON BREASTFEEDING! Do not give up! When my son was 4 months old I needed surgery. I was on morphine and it completely stopped all my milk. My son was at home being fed a bottle (yes, of that commercially prepared crap) and I was beside myself. I restarted breastfeeding when I got home 2 weeks later, even though I was dry. I used cloth diapers then to be sure he was hydrated, & had to feed him formula after our 10 minutes on each (dry) side. Then four days later, POW! I let down and nearly flooded the place. It was amazing. I went on to breastfeed sucessfully for years.
Remember, you can't ride two horses with one behind. You are not recovering from a vaginal delivery this time; you are recovering from abdominal surgery! It is a LOT harder!! (I know; I'm an RN.) See if there is someone from your local La Leche that you can talk to - these women were the glue that held me together, especially because I have no mother and my mother-in-law believes breastfeeding is "perverted" (??!!) Take what time you need to physically recover - the hospital won't let you languish or linger if you don't need to be there!
Relax, recover and keep on breastfeeding!
PS - my mother-in-law is also an idiot