Hey Lillady,
The half life of oxycodone is about 4 hours. This means if you take 60mgs all at once, 4 hours later there will be roughly 30mg in your system, then 4 hours later 15mg, then 7.5mg etc. People do vary though. If you take it spaced out it isn't quite as neat, but the principle is the same.
If you have been taking 60mg oxycodone daily for a year then withdrawals are definitely something you need to think about. Stopping it dead would likely be pretty unpleasant, so your best bet is to taper off. The ideal rate of the taper depends on what you can tolerate, really - slow is usually best. Some people taper with the drug they have been on, where as others switch to something else (methadone or Suboxone/buprenorphine usually). Others switch to methadone or Suboxone and remain on maintenance treatment for a period before tapering, or remain on it long-term. There are many factors which can determine the best plan for you.
There are things you can do to minimise withdrawal symptoms - loperamide is excellent for diarrhoea and other physical symptoms; benzos can help with anxiety and insomnia, although this can be risky as you may swap one addiction for another; antiemetics or 1st generation antihistamines can help with nausea.. there are other things too but my mind has gone blank. Looking after yourself, eating healthily as much as you can, exercising when you can etc all help as well. Opioid WDs aren't actually dangerous, unlike benzo/alcohol, but you do need to take care of yourself.
There are megathreads on Suboxone and methadone in the
Other Drugs directory, and I would also recommend checking out The Dark Side forum - it is the forum which deals with addiction and mental health problems, amongst other things, and you can get a lot of support and advice there.
Good luck!
