I get this nausea and dizziness from oxycocet and oxycontin. You might try adding dramamine (ask your pharmacist first, I'm not Dr) to help with the nausea. It's not going to help with your sleepiness but it might stop the oogy feeling. Either that or drink copious water, at least twice to three times what you'd normally drink in a day. Codeine can cause stoppage of the natural flow of things if you catch my meaning, which will also cause nausea.