Can I mix up my meds?

QI have had osteoarthritis in my hands for years and usually manage the pain with regular paracetamol. In recent weeks, the pain has got worse and my doctor prescribed me some co-codamol. It has completely got rid of the pain but leaves me feeling like a zombie. I thought about substituting some doses with my old paracetamol, but I think my doctor said I shouldn’t mix the drugs. A Co-codamol comes in three strengths: 8/500, 15/500 and 30/500. The 500 refers to the dose of paracetamol, so you can take eight tablets in 24 hours of any combination of paracetamol and co-codamol, but not eight of both. So, for example, you could take one paracetamol and one cocodamol four times a day.