It's impossible to know how strong/pure your dope is, via the internet, so to give an accurate comparison would be reckless. That said, methadone is much more powerful than many realize, and leads to countless overdoses due to re-dosing too soon because they think it isn't working. It can take a few hours before you reach peak effects. But knowing paterson dope, your tolerance to opiats seems quite small. When I first entered methadone maintenance a few years ago, I went in coming straight off shooting about 10 bags of newark dope per day, and 40 mg of methadone was enough to get me pretty sloshed. So in comparison, i would start out with no more than 5mg of methadone. Don't re-dose an hour later, though, thinking it isn't working when in reality it may take 2-3 hours for effects to really start to manifest themselves. Many people make this mistake, and hours later the effects of the two doses both peak and they end up taking too much and getting sick. (sometimes even over-dosing).
Be careful with methadone, man.. If you dont' know what you are doing it is one opioid better left for emergencies such as when you are withdrawing. Will 10mg kill you? Probably not.. But it is possible 10mg could make you sick based on your extremely low tolerance.
Be careful. I had a good friend die 2 weeks ago because of combining too much methadone with klonopin. Tread VERY lightly, my friend..