Lots of people have adverse reactions to medication and dressings. The most important thing to do if you have further procedures is tell your surgeon, your anaesthetist, your nurses, anyone who listens, that you had an adverse reaction to a drug in the previous operation. There are almost always alternatives to try.
Yes, lots of people sleep propped up after breast surgery. I know I did! Some women after reconstruction sleep in recliner chairs.
Drink plenty of water to flush the drugs from your system, and maybe see your GP if it doesn't stop.
Are you happy with your reduction? K xox