My experience dropping off methadone (admittedly limited.. I have since relapsed on heroin) was fairly pain free. This is, ofcourse, in comparison to what it feels like to be in intense WDs. I bought like 120mg of methadone and did a rapid self-taper over like 10 days. You will most likely have trouble sleeping for a couple of weeks after dropping off, and wake up sweaty. I found that I would toss and turn and wake up in a state of panic for no reason, throughout the night. Throughout the day I just experienced some lethargy and the usual hot and cold flashes that come with opiate WD. Hang in there! It does get easier every day. Soon you will start to feel AWESOME! Then you may experience some post acute withdrawal, but not for a few weeks. If you are really suffering I would recommend doing a slower detox, no need to rush! This is all based on my experience and it is of course, different for everyone. Good luck and congratulations on your progress! Shit ain't easy at all.
EDIT: I'd like to add that the time frames for you might/probably will be extended, due to the amount of time you've been on a high dose of methadone. Also, you may not be feeling significant WD symptoms yet, because you still have such a build up of the drug in your system.