Hi guys,
You are on the right forum. To get a lot of withdrawal information, go to the "I'm quitting oxycodone cold turkey...", and "Kicking the ox..." threads, as well as "Oxycodone withdrawal help..." thread. There's a lot of information there from the past 6 months, with a bunch of helpful posts. I don't have time to post a huge reply here, so I'd say go there but keep asking questions on more current threads, too.
The dizziness thing does not seem typical of the usual withdrawals. No one can give medical advice here even if we think we know what is going on, but we can share our experiences.
I agree with your friend that it may be totally unrelated. I've had some similar stuff going on, which for me turned out to be inner ear stuff from allergies. So don't automatically think "withdrawal" on this one.
Talk at ya later.
FT