I'm not a doctor, so this is completely subjective, but that sounds like a pretty big increase to me.
Back when I used, 30 mg of oxy would get me high, but 10 mg of 'done would get me utterly wasted and 20 mg of 'done would floor me. Definitely time for a second opinion IMHO.
And be damned careful with that stuff. I had a friend die from O/D methadone + alcohol, it happened extremely quickly. We thought she was asleep but in fact she had stopped breathing.
My personal experience is that suboxone is a way better treatment option than 'done if your oxy levels are low enough.
Best of luck to you!